Before migrating to Mac I was using a Belkin N1 router, which was very reliable. Now we're a mixed Mac (Macbook Pro, iMac, iPad, iPod Touches) and PC (PC's, Laptop, Modwright TP, Booms, Duet, Controller) household we switched to a Time Capsule with an Airport Express (as a wireless extender and for TV streaming).
If you are going down the Mac path using an Apple router is the best option for seamless integration, the AirPort utility that is integrated within Snow Leopard makes it so easy to use. I've been very impressed with the Time Machine/Time Capsule combination in recovering deleted files and making backups an automatic background process. You might want to consider the Time Capsule alongside the Airport Extreme.