There isn't much of a difference between the network adapters themselves, although if you get a Linksys or Netgear or one of the larger names you shouldn't have any driver headaches.
The routers are a different matter. Almost all consumer routers out there currently are crap. They have issues with dropping connections, freezing, even blacking out for periods of time. Linksys used to make good ones, but since version 5 they changed their firmware to something more problematic, and gimped the hardware (less cache memory).
Linksys does make
one non-gimped router called the
WRT54GL. (The trailing L is important, if it ends in G or GS it's the wrong one.) It uses a reliable linux-based firmware and has all the memory the pre v5 models had. If you'd like you can even flash the firmware with a 3rd party like
WRT-DD and turn a $70 router into a $1000 one. The stock firmware it comes with is fine if you want to stick with that, though. You seriously won't find a better router out there unless your budget starts at a grand.
EDIT: this is mostly in reference to the wireless router market. The Linksys wired series of routers are still fine, I think.