Gotham
2015
2013
2007
I think this is the closest to a perfect game I'll ever play. Each round is tons of fun, and the classes feel perfectly balanced. Every mode (including MvM) is stellar, and the community maps and servers mean there's always something new to experience. I've wasted weeks of my life to this game and I don't regret it. Its influence on internet culture and class-based shooters is undeniable.
Melee takes everything that made 64 great and expanded it. This game has the most technical depth in the series by far, and I could never see the competitive scene die out for that reason. There's some confusing design decisions that make it really hard to go back to if not for competitive (why no C-Stick in single-player modes?)
1999
2010
2007
1990