Linksys WMP54G v4 (Ralink)
I just got through installing this card on Slackware 10.2. for the 2.6.13 kernel. I decided to go with it mainly because it uses the Ralink chipset. Ralink has released their code to open source, and are paying serious attention to the Linux community. It's my belief they very much deserve our support. They provide drivers for 'g' and 'b' in pci, usb and pcmcia that are easily built and don't require NdisWrapper.
It was rough going since it was my first attempt with 802.11g, but luckily there is a wealth of information on the net about how to get it configured and running. A couple of links that got me over the hump...
It's really a pleasure having this kind of speed over 802.11b which is what I've used for years. Now I will attempt to get it going in CentOS. :)