So obviously theres an overall meta with some of the best heroes generally, but which are the best map-specific heroes? An obvious one is valla-battlefield of eternity.
murky, nova, tlv, brightwing, falstad on garden of terror. Never fight and just bribe all game.
Genji on Braxis. That is his best map.
You can easily rotate between the 2 lanes (specially using trait do get there faster) and force the solo laner off the point. Basically what you want to do is constantly go to the solo lane and deal as much damage as possible on the enemy laner. That way you make sure your offlaner wins the point by having more sustain. The second someone rotates top, you rotate bot again and join your team 4 v 3.
Post 7, with W cdr, you can easily speed up hard camp with your healer or someone else. As long as you get focused by all 4 mercs, you deal a lot of damage and get full cdr.
Because of the point control, boss and camps, both your ultimates are really good. People usually stay close to each other a lot in this map because of how the areas are, so you actually hit a lot of people with both ults, dealing a lot of damage.
Ah, and no, never go W at 16 and 20, even in this map, unless you are REALLY trying to meme and have some fun. If you want to be a serious player, don’t go those talents, ever.
Naz on Tomb can be devastating
Aba on CH
Aba on sky temple
Ana on CH
Tyrande Sylv + jaina on towers
Alex on infernal
- Braxis: sustain + AoE + strong solo. Globals and otherwise mobile heroes that can help gank are great.
- DS: 4 man rotation + good solo, no hard meta but globals do have high value.
- BoE: high single target damage(bonus for PvE) and TF focus.
- Bakamura: strong 4 man with TF focus. Optional strong jungler(you can do that with 4 man too). PvE as whole is the main point of this map as it gives tons of exp and Samurai is much stronger than actual objective since start.
- Tomb: strong 4 man with focus on wave clear.
- BhB. PvE, PvE and PvE. That all you need on this map, you will never have to fight without advantage if you play the map right. You can always jungle, push or turn in on opposite side of map from enemy team. Bonus points for heroes that can clear chest quick(DoT or high AS).
- GoT: macro focus with jungling so camps push during obj but those heroes should still be good for TF which is ultimately the main thing as team getting first obj almost always wins due to massive damage obj does. Globals are nice as it’s big map.
- IS: No real hero meta. You can split-push, macro, dual soak and TF so pretty much everything on this map assuming the comps allow it. Just avoid heroes that have their shots blocked by monsters. Strong zoning heroes such as Tychus Odin and Alex dragon are great here.
- WhJ: Globals.
- Volskaya: again no hard meta, as long as your 4 man can rotate the lanes in sufficient time and jungle. More about getting item camps as they spawn and strong zoning heroes are valuable like on IS.
- ToD: Map is 70% about controlling bot and getting sapper camps which is job for 4 man. Globals are nice, heroes like Yrel, Dehaka or Malth who can dual soak go well with the strong 4 man controlling bot.
- CH: Globals. Very macro oriented map so time camps for obj.
- HM: Just push lane and get camps while ignoring obj.
- Alterac: TF focus, globals are nice addition.
I see Rexxar repeatedly on Braxxis holdout, it’s a good first pick, he is perfect for holding the shrine in solo lane.
Lunara and Artanis are frequent first round picks on BoE due to their big early bonus damage to immortals, not that often picked early on other maps.
BoE = Valla 100% her Q build with the quest done for the increase damage for it = melting immortal
Hammer op on every map 
Tassadar TofSQ. He easy collects gems and hard to kill.