If you want "Linux friendly" avoid USB wireless. Their lack of support
in Linux is wide-ranging, very dependent upon the chipset and slight
chipset changes dependent upon time of manufacture.

If you have slots in a desktop PC, get an Atheros chipset PCI card.
Netgear NG311T is one such example that works with included Windows
driver and native Linux drivers. Change the model number just a bit or
buy one too new, after the manufacturer changed the chipset to a Linux
incompatible one while keeping the same FORMERLY good model
number...and you get an idea of the troubles facing wireless users.