I bought a crappy hdmi cable, thinking it would be oky since its only a cable, and i got gta4 and it doesnt look fantastic, anti aliasing is ugly, and its running on a 32" lcd hd.

Should i get a better one?
Make sure all of your settings on your console are set for HDMI. Other than that, I wouldn't know how to help. So I guess yeah, get a better cable.
"There is more stupidity than hydrogen in the universe, and it has a longer shelf life."
-Frank Zappa

"Where words fail, music speaks."
-Hans Christian Andersen
There are different types of HDMI cables, look them up, see which one you got...and which one you require.
There have been proven tests that only support the more expensive cable if it is over 12 ft. Otherwise there is no difference. HDMI cable prices are overinflated. I could look up the experiment if you like.