the best one i have seen for up to about 75-100 megabit is the r6220. you have to install 2 files instead of just flashing one and you have to log in to a special url to turn on debug mode but it was failry easy. its listed in the instructions on the openwrt website.
they are 80 bux new but ebay always has a flood of them for 20 dollars. ive bought 3 so far and all worked. cpu is 880mghz hyperthreaded and has 2.4ghz and 5ghz wifi that both work. a lot of routers you will check into have 10 different versions and you dont know which ones will work right. this router is very well supported and can be found cheap and has a very strong cpu with 128mb of ram and plenty of flash.
great router