I have been wanted to pick up like 3 with the b2g1 deal, but I want to make sure I get the best ones out there. I am really just curious to see the difference (I know its not much). Let me know your opinions, thanks!
I think Syberia is the best looking one. Other ones I know of are:
Atari Anthology
Dragon's Lair 3D
Enter the Matrix
MX Unleashed
Roller Coaster Tycoon
If your tv supports 720p, their are more and better 720p Xbox games than 1080i Xbox games. Also the Xbox 360 will play all backwards compatible games in either 720p or 1080i.
MX vs ATV Unleashed runs at 1080i, but the textures don't look any better. Still not bad. For showing off HDTVs, I'd stick with 720p games like Amped 2 or Soul Calibur II.