Well, you are going to need an HDTV and the right cables. Assuming that you have a PS3 or a late release 360, you need an HDMI cable. These go for about 6-10$ shipped on ebay, and about 25-50$ in a store. Since its digital, the monster cables deliver the EXACT same picture as the off-brand from Hong Kong. Alternately you can do component which is slightly lower quality but you can get a combination PS3/360/Wii cable for about $20 at gamestop.
As for TVs, definatly go off brand. I have had an Astar, Olevia and Visio and the picture/sound quality easily rivals the big brands that cost 50% more. The key here is patience. There are deals to be had, but you have to catch them, and you have to take a risk and be willing to buy things with no return policy online. I got my 37'' Astar for 599$ a year ago and my dad got a 47'' 1080p for 1000$ last November. Don't settle for anything less than 32'' even if it means having to save up money for a few months, and if you go >42'' be sure to get 1080p, even though very few games support it.