I'm recommending the Buffalo ones that are compatible with Open-WRT, currently. They're a little more difficult to flash the first time, as you've got to use tftp, but they don't charge more for the "linux version" and I feel like they're a bit higher quality. You can get into details about the processor speed and amounts of ram, and I think the Buffalo ones win on that front too. The most interesting is the Asus router that has USB host ports for hard drives built in, and is compatible with Open-WRT. I'd love to hang a raid array off one, thought I suspect the throughput might be an issue.

Matthew