They are hands-down, the best wireless routers out there!!! Why? They run on Linux and being so, a lot of hobbyist have created alternative firmware distributions that allow you all kinds of amazing functionality, e.g. boost the signal 10x over, QoS for reliable VoIP, use "alternative" channels, WDS, VPN, etc. etc....
All these megabucks features on a 60$ wireless router... can't be beat...
It has become the de facto standard for Internet Cafe operators and small community WiFi networks.
To find out more about the WRT54G series, check out
Wikipedia