Xbomber Box 2 - Homebrew Bomberman Clone
Madness Interactive X - Insane Xbox Homebrew Game - WARNING: VIOLENT CONTENT
Blob Wars: Metal Blob Solid
Cave Story X
I just found some videos of some really cool xbox home brew games.
All of these games are a lot of fun. I've played they heck out of them. Madness Interactive is really addicting! And Cave Story is a classic.
I love it when Home brew software rivals the quality commercial software. Seriously those games are so good they could sell them on Xbox Live / PSN / Steam, etc. I really admire the creativity and dedication of these talented indie developers.
I hope you like this stuff as much as I do.