Best Buy has one of their Insignia-branded (their house brand) ones that's around $279, if I remember right.
Circuit City has a 22-inch Element-branded (their house brand) one that's normally around $300 as well.
There's a 17" TruTech over at Target, with an included DVD player, I think it's in your price range.
There's a 20" Vizio unit that is over at Sam's Club, Costco and Walmart, though it's around $350-$400.
I think there's a 19" Polaroid that's also in your price range, seen over at Target, Walmart and Sam's Club.
There's a Samsung 19" that's all over the place, as well as a Toshiba and Sanyo.