Go with Buffalo. If not Buffalo, Belkin. Must have WPA.
Buffalo routers and adapters will give you MUCH better reception than any of the Belkin, Linksys, D-Link, or Netgear stuff. The strength of the signal is ridiculously high. The antennas are are so strong that I've gotten 50% better reception using Buffalo over Belkin.
If you must go with one of the big advertisers, just go with Belkin. They're much cheaper, their web based configuration is much more robust, and the reception is NOT any weaker than the rest.
Finally, make Blessed Mary, Ever Virgin sure that the router has WPA encryption. It is much easier to set up than WEP, and is much harder for an outsider to decrypt or hack.