Bizrate, Newegg.com and Shopping.com are some sources where you get to compare a lot of products. Discussed below are a sampling of products at a particular price point that is considered the most comfortable pricing.
HIS H260XTP512DDN-R Radeon HD 2600XT from Hitech card earned a review of 5 star from 68 users reviews. At under $100 is good value for money for the product you are looking for if you are on a limited budget. It has 512 MB memory ion board. Larger amount of memory on board buffers incoming video data and generally larger is better. The memory bus is 128 bit wide which spells fast speed on data transfer with GDDR3 memory. It supports HDCP. It has HDMI and DVI outputs.
PNY VCQFX370-PCIE-PB Quadro FX370 is another good product at $124.99. This is another 5 star product at the same shopping site. It has 64 bit wide memory bus with 256 MB of on board video memory. Performance wise likely to be a little below the performance of the first product discussed.
VisionTek RADEON HD 4670 is a 1 GB, DDR3 memory card and is available for $95 to $140 depending on where you look. This earned a 4 star review rating from more than 8000 users at Best Buy. The manufacturer clearly mentions support for all the relevant compression technology as well as 7.1 surround sound. HDMI, Component video and DVI connectors supported.
The above are samples of what products are available. The sites indicated give you the opportunity to do comparative shopping but do check out the manufacturer page to get a clear idea of the specs and before finalizing on one. All three sites have products in different price ranges. $100 to $150 was taken to be the consumer sweet spot and we looked at only products in that price range.