I've been having bad experiences with the Vizio lcd's. At this point I'd recomend avoiding them. I'm on my third screen in the last few months and am having more issues, meaning I'll have my fourth tv before long. For reference my experiences are with the VX37L 37" and the GV42L 42" Vizio lcd's.
The Olevia lcd's are highly recommended around here at their price point, but I have not been able to view the models I'm interested in in person yet. So I can't offer my opinion on them. The Sharp Aquos lcd's that I've seen have very nice pictures as do the Sony Bravia's, but I'm not sure of the pricing on them. You may want to look at them and see what you think.
Jack