I have been using an old Linksys, but since I purchased it Linksys was purchased by Cisco.
There are some things to think about in a router.
Total number of connections
Support for a print server
VPN Virtual Private Networking - Connecting to a work related Lan
IP Phone Support
Type of firewall it can use
Ability to run the firewall wide open for a game server. Sometimes there is one port you can use to go around the firewall.
Opening up ports for certain games or IM Instant Messaging like AIM.
Advanced Firewall Filtering for blocking certain kind of attachments that can be executed.
Routers can be so complex the average user can not figurethem out or so cheap they have no options at all. If you ever planned on using an internet phone service like Vonage, IP support might be nice but it just costs more. Also if you want a Wireless connection for a Laptop or can not run wires like in an apartment wireless might be a good idea. You could have one to four wired and as many wireless connections. If you are going to use wireless it is best to get a "G" class wireless since that is the basic fastest Protocol for wireless. If it supports both "A" and "B" that is fine too.
How far apart do you plan on putting the computers?
Can you run wires?
Things to look for:
A Wireless cost just a little more, but if you want multiple connections, for Wired you also have to buy the cables and there is some cost associated with wires, but it is a lot faster for downloading and for playing fast online games. Some building have things that interfere with Wireless transmissions. If you have some friends with Routers or multiple computers you might try going to their house to see how they set theirs up. I keep all my computers in the basement, so I dont care if the cables are hanging from the rafters. Some people are more picky.
Might try looking at a Best Buy or Sams or something like that.
Other Brands:
D-LINK
Netgear
I like to buy mine online from
New Egg
Amazon
ZIP-ZOOM-FLY
Office Depot
Best Buy Routers
A couple of these are also brick and mortar stores. Some people like to go look at what is at the store simply because they dont want to use a credit card online or they like to see the selection. Every brand probably has both good and bad products and models that just have better features. I am partial to the Linksys models with the blue and black case. I dont like the rectangular boxy looking models. Some of them appear to be really cheap.
If you want wireless maybe go someplace like a coffee shop where they have wireless and look at how well it works. To me wireless is not fast enough for a big-time downloader. However, you can have wireless and wired in the same product and get the best of both worlds.