The Binding of Isaac is probably the game I have played more than any other, hundreds upon hundreds of hours. It's also one of the few games I've ever triple dipped: PC, Vita, Switch.
Probably world of Warcraft. Nothing compared to a lot but my /played was upwards of 40 days I think.
Binding of Isaac is worth a mention. Only game I've triple dipped on. Got back into it a month ago and it's my go to at the moment. Starting to get burnt out on it though.
Wish I could find another game I like that much. As I get older it's harder and harder to get sucked in. The amount of times I've bought/rented a game only to play for an hour or two and then stop and never touch again is embarassing.
Black & White 2 (as in the Lionhead Studios game, not Pokemon). I dunno, I just absolutely love the idea of having the power to summon a volcano. Hahaha.