World of Warcraft - It effectively destroyed my parents' marriage, what more do I need to say?
League of Legends - Toxic community, F2P BS, waaaaaaay too competitive for my liking, and I've personally seen it make my friends rage like crazy. Why do people even play this game?
Hearthstone - More F2P/P2W BS, and you have to spend an insane amount of time playing to get any good cards if you don't want to pay
World of Tanks - Looks boring as hell, plus F2P/P2W, overly competitive, yada yada. Are we starting to see a pattern here?
Any mobile F2P multiplayer games - They're pretty much all P2W. Some of the single player ones are OK, but anything with a multiplayer or social media aspect is automatically rejected in my books.
Oddly, Call of Duty is not on my list. Why? Because none of the games are F2P or P2W, the more toxic players are easy to ignore if you mute them, and the splitscreen multiplayer on the console games is actually pretty fun, at least on the Treyarch releases. That said, I find the Infinity Ward games to be boring for the most part, and I hate how hacker-infested some of the older games have become. Black Ops 1 was still very playable in 2012, two years after release, but playing it again in 2014, there were glitches and hacked lobbies abound.