For me, its NATIVE or nothing, i don't like messing with wine.
Humble Bundles, are darn worth it, i get my game time from most of those games, currently into "Snapshot" and "Offspring Fling".
FPS: Quake 3/4, Unreal 2004 Prey, and Warsow, Xonotic, though i don't seem to play much of those these days
Freeciv, Hedgewars, i love playing these with online pals.
I also recently purchased "7 Wonders: Magical Mystery Tour" (big fish games) from the app centre- good stuff.