How does your 2600 handle regular TVs? Have you thought about a 7800? I keep my 2600's around (a reall 2600 and a Sears Tele-Games) for neat-sake. I picked up a 7800 inexpensively several years back and did my own S-Video hack on it. Same with my 5200. The 7800 will play 2600 games just fine, and the games made specifically for it are really nice.
