The good ones (SC2, OW) are running on life support now with barely any updates. Blizzard died when they merged with Acti and now it's a slow descent to 0 players. D3 was also pretty good well after release (no RMAH) but that was released in 2012..
Their remastered Diablo 2 is on track to be a hit, but it won't be out until later this year.
sc2
Hearthstone for casual play. do not sink too much money into it. you can play Hearthstone for free if you do quest and craft a deck that you really like to play
which sadly isn't supported on M1, and who knows if Blizzard will ever release a patch for that.
A hot take but I was really disappointed by it when it first came out. While waiting for it to be released I discovered Total Annihilation which really seemed like the next generation of RTS. When Starcraft came out it felt like WarCraft 2.5 or 2 with ramps. Sure the plot was much better, and the races were more differentiated, it did not feel like an evolution of the genre: just more polish. After that RTSes haven't grown IMHO outside of Sins of a Solar Empire, Total War, and Supreme Commander.
I think that WoW is a good game for some kinds of players.