Walmart has a 37 inch 1080p Vizio right now for $350. all the others I saw that were smaller were 720p, so maybe theyll have something on black friday.
I myself have a 42inch 3d vizio and I'm quite happy with it, but thats a little out of your budget lol. Just have had good experience with Vizio so I would recommend it.
http://www.walmart.com/ip/VIZIO-42-C...420VX/15992330 is what I have and its now $528
lol
edit: didnt see you wanted 120 refresh rate...think that usually bumps the price up quite a bit, and after looking everything 120mhz is 40 inch and up.