D-Link DGL-4300 Wireless Gaming Router, 4-Port Gigabit Switch, 802.11g, 108Mbps, 5dBi
http://www.amazon.com/exec/obidos/redirect?tag=r5un7ejl-20&path=ASIN/B0006TIA02/
"High-Performance CPU to support thousands of concurrent connections – ideal for P2P applications and multiplayer interactivity"
Only $140.
A recent article on Engadget "Ask Engadget: Which wireless router" flamed Linksys, but praised D-Link a lot, and then when I saw this router, I knew it was the one. Plus it has a great rating on Amazon.