QUOTE(Clockface @ Jul 9 2008, 04:55 AM)

Quake Arena: An all in one Quake + mod package that turns Quake into Quake 3, sort of. You get bots to fight with, most Quake 3 weapons and some great Quake 3 (and other) maps. I don't like Quake 1 or 2, but I do like Quake Arena. And it supports user made maps, though the bots seem to have trouble navigating some user maps, though the bots play fine on the included maps.
Polygun Wars: A great version of the XBox 360 game Polygon Wars.
Doom: A great version of Doom (there are several ports of Doom, I use the one that uses [SQUARE] and [X] to straff, and the right shoulder button to fire, and supports user maps.
Duke Nukem 3D: This would be my favorite PSP Homebrew by far, as DN3D is still one of the best games ever made, but sadly the PSP doesn't have enough buttons to control the game fully. Also, this port doesn't seem to suport user mods,
Also there are at least two Suduko programs, which is good as Suduko can be very good.
I wish someone would port Alien vs. Predator (the original, and still the best, first person shooter PC game), as it's source code is available (it's currently being ported to the XBox) at:
http://liberatedgames.com/gamelisting.php I'm pretty sure we're talking X-Box here, Clock. You got me extremely excited when I saw Polygun Wars. Unfortunately, it's not ported to the original box at all.
But anyway, the best Homebrew games I've played on X-Box would have to be:
Super Mario Wars
Xlime
Dead Babies Extreme
DOOM Legacy (NOT xDOOM)
QuakeX
Quake 2x
Quake III Arena (BUGGY, but a great app to have available at your disposal)
Star Wars (forget what it's called...it's not really fun, just a little more impressive than most)
Aftershock Pool (gravity can glitch out like crazy, but it's the most impressive homebrew out there, I think)
Any emulator made by X-Port (except for virtual boy) is fantastic.
Noiz2sa is pretty cool. Almost the same as...
rRootage
Breakout 3d is okay
and...of course...the almighty...XBMC. If you don't have it on your X-Box, get it. In my opinion, it's the only app keeping the X-Box alive.