These are commanders that I mostly play and I included others but I rarely use them but might use them now from their prestige bonuses. This mostly from my playstyle and my opinion and I stated only the obvious picks and reasons why as I know there are other viable prestige picks other than these.
RAYNOR:
P3 (REBEL RAIDER)
(+) The Starport no longer requires gas to build, and its units cost 30% less gas. Vikings, Banshees and Battlecruisers increase top bar ability cooldown rates by 1% per supply used
(-) But all combat units cost 50% more minerals.
Why: This is a definite win-win situation since the 50% more minerals can easily be negated by MULE spam for minerals and can build early starports for early BC spam
KERRIGAN:
P3(Desolate Queen)
(+) Assimilation Aura resource drops are increased by 100% and Kerrigan has access to Kinetic Blast and Crushing Grip.
(-) But Psionic Shift and Leaping Strike are unavailable.
Why: This is another win-win situation since Leaping strike and Psionic shift are replaced by Kinetic Blast and Crushing grip which is definitely a buff since Kinetic blast can target Air units and Crushing grip has low cooldown iirc from campaign. Resources means more expensive units early and upgrades.
ARTANIS:
P3(Nexus Legate)
(+) Any combat units standing inside the existing Projected Power Field is teleported to wherever the new power field is projected, and the cooldown is removed.
(-) But Project Power Field requires 10 energy.
Why: Artanis always had low mobility for his army and with this prestige he can instantly teleport units on defending or attacking with instantly similarly to fenix arbiter mass recall but with no cooldowns and only 10 energy which can be accumulated fast with masteries.
ABATHUR:
P3(Limitless)
(+) Ultimate Evolutions are uncapped in number.
(-) But Ultimate Evolutions require twice as much biomass (200) and the effects of biomass are less powerful.
Why: Why not? It’s every abathur players ultimate dream of having 5 or more of each hulking units on their screen only downside is it would take longer to make one which the buff to his double biomass chance can be handy.
NOVA:
P3(Infiltration Specialist)
(+) Nova gains permanent Super Cloak (similar to Abathur’s toxic nest which cannot be detected and targeted but can be damaged by AOE or splash damage), and her abilities have a 50% increased radius and 50% reduced cooldown.
(-) But Nova cannot switch to her Combat Suit and loses her Super Cloak for 4 seconds every time she either attacks or snipes an enemy.
Why: Nova becomes the solo ghost operative she was meant to be. 50% CD especially her sabotage drone (the explosive) with increased radius looks like you can do a lot of damage added with her powerset 2 that increases primary ability damage that also affects snipe. If i’m correct it also affects the CD of her NUKE so yeah… that’s a lotta damage! Idk if her snipe gets splash though. Also with the super cloak she can go inside enemy bases/objectives and plant explosives or just nuke the hell out of it.
STUKOV:
P3(Lord of the Horde)
(+) Infested Bunkers spawn Infested Troops 200% faster.
(-) But they no longer have cargo capacity.
Why: Bunker spam is yet again going to be viable only downside is having no defense inside or while moving them but it can easily be negated by broodling spawn or calldowns and possibly building barracks near them since Infested marines also had been buffed to costing 15minerals instead of 25. Oh yeah RIP FPS too.
FENIX:
P3(Unwavering Vindicator)
(+) Avenging Protocol effectiveness increased by 100%, and Champion A.I.s that die refund 75% of their base unit cost.
(-) But Champion A.I.s do not gain additional life or shields and have reduced attack range.
Why: Fenix’s gameplay revolves mostly on his champions and removing the enhanced Life and Shields can be managed by using his conservators a lot more and reduced range means the champions are going to be targeted primarily which is the point of the avenging protocol and u get a refund of 75% means you can just build more only losing 25% of its total cost. Also this means powerset 2 increased Life and Shields become useless. Seeing a rabid kaldalis with cleave against lings would be a sight to see.
DEHAKA:
P3(Broodbrother)
(+) Dehaka gets a clone
(-) But If one of them dies, the other dies as well and they both have 35% reduced max life.
Why: Prepare for trouble and make it double! DUOHAKA seems to be pretty broken in the right hands the only downside is the death mechanic and early hp. I can also see the issue on how would they collect essence? Do they level up simultaneously and have the same exp? Either way it’s going to be fun having 2 godzillas with all his skills on the map late game. The only worst thing would be going to need more micro.
HAN & HORNER:
P2(Wing Commanders):
(+) Horner’s units’ gas costs are reduced by 20%, and his charge cooldowns are reduced by 50%.
(-) But Galleons are capped at 2.
Why: 20% gas costs are pretty huge since horner’s units are all gas heavy esp his BC. With this reduction, you can probably call more of his units early as long as they have charges and the 2 galleon cap doesn’t really matter much since most of your minerals will go mostly to mira’s units early instead of more galleons and they train fast anyways. The 50% CD on charge cooldowns means more units available that u can get for the whole game as long as you don’t let them at 5 charges.
TYCHUS:
P1(Technical Recruiter)
(+) Outlaws’ active ability cooldowns are reduced by 35%.
(-) But their cost and time between recruitment is increased by 50%
Why: I chose this over Lone Wolf simply because you would always use the outlaws close to each other since they all have synergies and especially needed for healing all of them at once plus not all of them have good damage. Sirius as 1st would be the strongest choice and u can spam turrets most of the time. Rattlesnake is always a must 2nd or 1st choice and more heals. Increased cost and time can be negligible as long as you’re spamming your skills correctly while waiting for the next outlaw.
ZERATUL:
P2(Knowledge Seeker)
(+) Zeratul can collect unlimited amounts of Artifact Fragments.
(-) But his combat units cost 25% more.
Why: UNLIMITED POWERRR!!! This is definitely OP add it to his mastery that reduces artifact cooldown (up to minimum of 120secs) means u can collect artifacts within 2 minutes of each other. Let me remind you that he gains additional shields (+50), increased Shadow Cleave damage (+10), and additional charges of Blink (+1) with each Artifact Fragment he finds so imagine getting 10 artifacts he can probably blink 10times to the edge of the map while one shadow cleaving anything every 12 seconds. You can ignore 25% costs as long as you focus on using zeratul himself for early mobs.
STETMANN:
P2(Best Buddy)
(+) Gary’s health and damage increased by 100%.
(-) But his movement speed is 90% slower outside stettzones.
Why: Super Gary has 45 base attack and now 90 with the prestige means he can hit like a truck. Add that to stetellite overcharge on F.A.S.T. config (the BLUE one) he gains 20% more attacks speed and that’s a lot of damage in a few seconds. 90% slow can easily be negated by his skill making a zone from himself. 200% health also means from 1000 to 2000 and he’s pretty much unkillable on while on green zone.
MENGSK:
P1(Toxic Tyrant)
(+) Contaminated Strike’s fear lasts 200% longer, its damage-over-time effect increases damage received by 100%, its cost is reduced by 20%, and its cooldown is reduced by 66%. Troopers provide Imperial Support while operating Earthsplitter Ordnance.
(-) But Nuclear Annihilation is unavailable.
Why: As a mengsk player, one must always build ESO atleast a minimum of 4-6. With this prestige, you have more CC from fear duration (base was 5 seconds now 10 with prestige) , more damage overtime (more if you pair with the mastery at the cost of losing gas cost mastery) , cost and cooldown reduction (30 base CD) and most important of all getting imperial support from ESO manned troopers (which should be a feature not prestige locked in the first place). Nuclear Annihalation disabled can be overlooked as long as you spam Contamination strike. Only downside is you cannot damage buildings with it.
(EDIT) Added other commanders I rarely use but seems strong on paper and possibly try now
SWANN:
P2(Grease Monkey):
(+) Turret upgrades are now 100% more effective
(-) But combat units cost 50% more gas.
Why: Turret uprades refer to KMC autoloaders (increases atkspeed by 25% on all turrets) and fire-suppression system (All buildings will initiate auto-repairs when below 50% health, repairing them back to 50% health). This means more dps from turrets overall which can help on earlier expansion openings and static defense plays. The 50% gas cost looks a bit much but his useful units usually don’t cost that much gas such as goliaths and siege tanks (initially 50 gas and 125 gas respectively, 50% means 75 gas and 187.5) which is manageable since swann gets a lot of gas anyways.
ZAGARA
P3(Apex Predator)
(+) Zagara gains reduced ability cooldowns, additional health and energy regeneration, and access to Deep Tunnel ability
(-) But Mass Frenzy only affects Zagara’s summoned units and herself, with combat units costing 25% more.
Why: The rare times I use zagara and the obvious one would be mass banes and scourges since it’s her signature units. 25% more cost might be a worth a shot for having a more hero focused gameplay with reduced ability cooldowns and spamming skills like baneling barrage and infested drops for overall dps increase without investing in resources. Added with her masteries focusing on herself and she might be able to solo some maps.
VORAZUN:
P3(Keeper of Shadows)
(+) Time Stop is now targeted, and all Shadow Guard who have died are resurrected at the target location (Timestop still covers entire map but the targeted locations spawn the shadow guards)
(-) But the Shadow Guard duration is reduced by 40%
Why: If I get this correctly, shadow guard summons lasts for 60 seconds (120 with full masteries). 40% means 60 secs become 36 seconds (120 becomes 72 seconds) and a cooldown of 2 mins. This becomes an ability that accumulates every usage if expired units count as dead ones which can mean an army within timestop that can annihilate enemy encampments within the 20 second timestop and even more powerful with the timestop cd mastery that makes up for the reduced duration. This is unless emergency recalled shadow guards and already summoned shadow guards cannot be resurrected again via another timestop.
KARAX:
P1(Architect of War)
(+) Repair Beam is now 100% more effective and can target twice as many structures, Unity Barriers now target defensive structures, and Chrono-Abilities now affect defensive structures, increasing their attack rate.
(-) Repair beam may only target structures, and Unity Barrier no longer protects units.
Why: The Karax dream of unbreakable static defense with repair beam focused on defensive structures from 10hp per second to 20hp (19hp with masteries to 38hp per second) . With the repair beam upgrade, 10 structures can be repaired at the same time which is pretty strong on static defensive commanders. Unity barrier adds a bit more tankiness while overall removing the benefits from his units which can still be viable not just as tanky as before. Lastly the chrono ability as an offensive ability can be really handy for both offensive and defensive static placements and can synergize with other static defense commanders such as Swann.
ALARAK:
P1(Artificier of Souls)
(+) When a nearby Supplicant dies, one of nearby non-heroic mechanical combat units gains permanent increase in attack speed and damage
(-) But Alarak’s Deadly Charge and Destruction Wave deals 50% less damage
Why: This prestige focuses on a late game army similar to Abathur’s biomass mechanic but only affects mechanical units (Slayer, Vanguard, Wrathwalkers) together with his signature late game ascendants. The sacrifice on alaraks skill dmg can be ignored in the long run since you can spam destruction wave anyways with 5 sec cooldown and deadly charge in 15 secs. I don’t know how much increase per supplicant but as long as you manage to protect them and if it has no cap then we can expect a late game mech army competitive with other commanders as long as you have minerals for supplicants. This also raises the questions if sacrifice skill from ascendants count as supplicants killed then it would buff the ascendant and one mech unit.
Feel free to add yours in! 
