TF2 is one of my highest as well, but only half as many hours as you! Lots of hats… cashed out all my unusuals for an Index.
Highest is probably Diablo II+D2R, played every day in my teens, from when I got home to when I slept. Then I started playing while botting. Has to be 3k+ hours. Never been so addicted to a video game.
Same, my most played game ever. I find it funny, at least to me, a game from 2007 thats barely supported by the dev is significantly better than the other modern derivatives of tf2 like overwatch and marvel bandwaggon money maker.