1) Dota 2 (best gameplay of all games out there by a huge margin for me)
2) Warcraft 3 (infinite replayability because of custom games, has the best tower defenses)
3) Unreal Tournament (the soundtrack and some simple, quick action always keep me entertained)
4) Portal 2 (best jokes, some nice puzzles)
5) Diablo 3 (too grindy, but is okay for some nice slaying through hordes of monsters with character that feel relatively distinct)
6) Diablo 2 (too grindy, but invested a lot of hours into it in the past)
7) The Walking Dead (I really liked how Lee and Clementine interact and grow together in Season I)
8) Mirror's Edge (only jump'n'run (plattformer) I enjoy playing, cool style and soundtrack)
9) Runaway - A Twist of Fate (one of my favourite adventures together with some wadjet eye games)
10) Super Street Fighter IV / V (the fighting game of my choice)
Top 1 is very easy to decide, then the two other in top 3 are kind of still easy to choose for me personally... after that it get's super hard.