If your going to use your monitor as a HD TV, I'd recommend the gigabyte refurbed 6600 from newegg. If they are still in stock, I got mine for around $60, it comes with the HD converter and mine easily overclocked to 550/700.
For the limited info you gave, there are a number of sub $20 refurbed cards that could do what your looking to do available from various vendors depending on what's in stock. Any card within the last several years will support 32 bit color and 1600X1200, but you'll probably be looking at something a bit newer for the DVI connection. Also, even for people who say they won't game much, I'd recommend a good gaming card depending on what games you plan on playing. Even if you only play a game like Doom3 once every few months, it's still nice to actually be able to play the game at decent resolutions when you do play. The 6600 overclocked would fit this bill perfectly.