"Linksys makes some fine wireless broadband routers, but one of the best things about these devices is that their firmware is based on Linux and can be replaced with third-party software, allowing anyone to have the functionality of an expensive, professional-grade router for less than $100. The GPL-licensed DD-WRT package offers lots of enhancements over the stock Linksys firmware and supports a wide range of hardware, including models from Buffalo, Belkin, and other vendors.
"Noteworthy features of DD-WRT are powerful quality of service control, which allows bandwidth optimization for specific programs or hosts; Wireless Distribution System (WDS) with support for WPA encryption; and RADIUS authentication for more secure wireless connections. Check the project's wiki for a complete features list..."