If you want to play NES...

http://retrousb.com/index.php?productID=133

I bought 2 of them and they work.

I would definitely go with an original Xbox, either hard modded or soft modded. FCE Ultra, Snes9x and several other emulators and unrelated apps have been ported to this platform and will run games amazingly on your TV. Not to mention, XBMC and a network link to a desktop/server to play your media is an absolute must.