If you like arcade games and have a gamepad with dual analog sticks, I would highly recommend Grid Wars 2. This is a fan-made version of 'Geometry Wars Evolved' for the xbox 360. Zero load times, insanely fun and very addictive. You control a small ship that can move in any direction while shooting in any direction. The screen fills up with different shapes (each displaying different movement characteristics) and you have to shoot them. If they touch you, you die. Sounds lame but it gets crazy-intense.
I have FEAR, HL2, Doom3, Quake4, etc and have gotten way more enjoyment out of Grid Wars 2. But that's just me.
It was a real bitch to configure the gamepad, but once I got it working it's been pure gold. I wouldn't recommend playing using anything else, however...keyboard/keyboard+mouse combo's for this game just don't do it justice.
Already got that with my wireless 360 pad :D :D :D
Anyone else?