I’ve owned a few routers in my day, but have never really been happy with any of them. Coming from a tech background they always seemed to be dumbed down and complicated in the worst ways. All that has been changing though. Thanks to Linksys being forced to release the code for their routers due to the GPL, people have been able to take that and write some fabulous code.
My favorite so far is the Tomato Firmware. It is lean, fast, and full of fantastic features. The QoS works wonderfully to prioritize specific network traffic. The interface and graphs powered by ajax are clean and informative. The router even has a site survey to see which wireless channels have the most traffic.
If you are comfortable flashing your Linksys router, I highly recommend the Tomato firmware.