in linux(really anywhere) you are concerend with the chipset, not the actual card model. All of these companies are really selling the same stuff, they just slap different packaging on it. To make it even more maddening, some will completely change the chipset inside, while making only a minor revision change to the model number!
Things that work well: prism2, prismgt, atheros, orinoco.
Things that work much less well: broadcom, TI acx100
This link may be a good place to start: http://www.seattlewireless.net/index...wareComparison
Personally, I have an old Rev1 Netgear WG511 thats prismGT, and a Netgear WG511U thats atheros. Both work fantastically.