Originally Posted by Kujo
The games still look great on SD, but you do really need a HDTV to get the full effect. That being said, it's still worth buying if you only have SDTV. Plenty of people own the system, and don't have a HDTV.
HDTVs are so damn cheap now. You can get a 32 inch LCD flat for like $500. Just look for deals online. You wont regret it if you own a 360.