I had (still have actually) an older Linksys WRT54G v2 that started acting funny.
As it happened, IIRC, Newegg put the following on sale for like $14.99:
Linksys LINK-M20-RM Valet Plus Wireless-N Routerhttp://www.newegg.com/Product/Product.a ... 0AT0GN8961
Current price is all of $27.99 for 802.11 B/G/N and 4 x 10/100/1000Mb ports.
I loaded it up with DD-WRT firmware and it's been working great. The standard firmware was fine if you wanted something simple, but DD-WRT offers a ton of more and advanced options for those so inclined.
It was a little difficult finding the correct firmware and getting confirmation, but it loaded up fine (use IE only to upgrade the firmware from stock the very first time, after that I've used Palemoon to update firmware) and I've upgraded the firmware twice since then, no issues at all. Very advanced and FREE firmware update from DD-WRT.
You can get the DD-WRT firmware at: http://www.dd-wrt.com/site/support/other-downloads
(Downloads, Other Downloads, eko, V24-K26)
SVN18946 04-07-2012 is the latest version, working great.
I apologize for the very high price of this particular router.