LCD tv shopping help?

i got the 37 inch vizio and to be honest, I think I wanna take it back. After the warranty and tax I got it for 1043 from sears with no payments or interest for 1 year. But I dont like the picture on some channels. Im wondering if it has anything to do with direct tv. I was considering trying HD before I take it back. I dont feel like I got my moneys worth. The 32 inch vizio in the store looked great even compared to the LG sitting below it