I'm assuming you mean plasma vs lcd. Id go lcd.
Samsung or Sony are the best quality, I'd prefer samsung.
If you have a lot of windows\lights you might want to have a screen with a matte instead of a glossy finish.
120hz is pretty sweet, most of the new tvs are coming with it.
Also, i might recommend once youve nailed it down to a few tvs going to a store and looking at them, but ultimately, order with amazon. The price often comes in a few hundred dollars cheaper, and you dont pay sales tax.
Tell us about the rest of your setup (and your price range) that might help with the recommendations as well.