Basically any known brand router will do, Belkin, Linksys, Netgear etc.
Just make sure, you buy N type, which is faster and has better range, than older, G type.
I run a lot of torrents and up to 7 wireless devices at a time. I'm doing this on a cheap Trendnet (TEW-652BRP) router. I had a lot of problems initially, anytime a new device (over about 3) that tried to connect wirelessly caused the wireless to crap out for everyone. I fixed this by setting static IPs for certain clients (MAC addresses) and all is well now.
I would do a google search for your internet provider and find out what routers most are using.
It appears "Clearwire" has issues with some routers that work for most everyone else. Sometimes it is just the version of router, not the make that is the difference..."D-Link"
I would find the best price for a router that meets your needs and then research problem areas listed on the forum for that router. If you have a cable modem, DSL, or satellite internet system, there are always certain brands or models that become problem children when trying to work with whatever associated system. The forums will usually point out the fix or what not to buy for a particular provider.
Basically any known brand router will do, Belkin, Linksys, Netgear etc.
Just make sure, you buy N type, which is faster and has better range, than older, G type.