I need help setting my Samsung - 32" 720p Flat-Panel LCD HDTV for my xbox 360.?

I just got my tv 3 days ago and plugged in and etc with the xbox 360 and wii. My xbox 360 is a premium and I changed its HDTV Switch on and put it on 720 from the display on the Xbox 360 dashboard. But yet it still looks like crap, the out line of the guys are kinda pixelly, my orginal tv look better then this. Is it somthing I have to do on the TV ? Like Sharpener max out or somthing? Or do I have to buy a elite with the HDMI port? Help me please. I'm about so close to returning this tv and sticking to the regular. 900 dollars of ugly graphics.

you have to go in your xbox setup and change screen settings to hdtv