I am going to give you both the most obvious answer but also my oppinion and personal experience.
Okay, most obvious is any of the S - Tier builds right now. If you visit maxroll.gg and go to pushing tier lists you can see the strongest ones there, but you can also deduce what is really strong by searching leaderboards in the game. Obviously a build that has 100 sub 10 minute clears is going to be stronger than one that has barely a couple of clears. However, some of the S-tier strongest builds aren’t the easiest to play, or require specific rotations and do damage in small windows, or they excel at one thing and suffer at another, etc. You usually mitigate this by practice, skill, paragons, good gear, luck on affixes of monsters, map design, pylons, soul shards (like the ring of fire), etc.
This season I decided to main Crusader and didn’t know what to play at first. Roland got buffed and seemed strong but is terrible at single target. Akkhan is probably the strongest choice, but also attrocious at single targets so rift guardian fight tends to make the gameplay boring for me. I had a relative easy time clearing GR150 with LoD Blessed Shield and Invoker thorns. I highly recommend the first, if you have the patience to farm all the gear as ancient/primals because it is a Legacy of dreams build. But it does everything great. It is tanky as hell, it clears screen fast, it is decent enough at killing the Rift Guardian, it benefits greatly from every pylon. It even doesn’t use the ring of fire soul shard which I don’t like but instead you use the attack speed and crit soul shard so it feels like you hero basically does all the damage and not some proc on the floor every 100 kills. It has very consistent damage, pretty simple gameplay and rotations, straightforward skills and buffs. To give you an idea of how strong it can become, I currently farm GR137 in 3 minutes and can clear whatever map the GR150 throws, pylons or no pylons. As for toughness, well I can tank everything, even molten explosions and arcane beams in GR150 and my followers cheat death procs once every 5 hours or something but I also have great gear and more than 30k main stat. The only donwside is it is a bit hard to gear because a) it is LoD so ancient/primals in every slot and b) it requires cooldown, crit, attack speed, area damage, every possible offensive stat. So some pieces are a pain to get as perfect. I am position 4 in EU leaderboards with LoD crusader but the other top 3 use a different LoD with thorns and bombardment which can is arguably stronger in a good map. And I never fished with it, it was just a decent map with 2 good pylons at a very good time and place. Check my profile and then click Europe region if you want to check what skills and items I use. The only changes that I make between farming and pushing is
a) gem for farming: molten wildebeest’s gizzard to protect the squirts amulet and for pushing: bane of stricken to take down the boss faster
b) Weapon soul shard for farming: death blow and for pushing: 50% more poison damage
Invoker on the other hand is a bit trickier, it deals tremendous damage in short bursts and very specific time windows. This has to do with the soul shard that allows thorns to crit, so basically you blind / stun enemies and then you go crazy on them but it only lasts a couple of seconds and then you have to wait for your rotation again. The thing is that monsters build up crowd control resistances after a few stuns/blind/freeze/etc and you have to reset their resistances. That said, if you are unlucky and spawn many juggernaut elites you can forget your push cause they cannot be crowd controlled hence you cannot crit them.
I also played GoD, Impaler, PoJ monk, and Inarius Nova this season. I couldn’t do GR150 with them, but that doesn’t say anything necessarily. Inarius and PoJ are considered among the top builds, it is just that I don’t find their playstyle that enjoyable so they don’t motivate me to push them to their limit. I aim to try again at some point with other classes and builds but so far I have a blast with crusader and my luck with primals keeps improving.