When I've the time, one of my favorite stops online to spend some happy gaming-related time is 1KM1KT (aka 1000 Monkeys, 1000 Typewriters). To be sure, there's a mixed bag to be found there, but at its best, it's a place where you can download and garner inspiration from a ton of free RPGs.
I really liked A+ Fantasy, which I found over there (and its 2d6 goodness), and recently I found a couple more I thought I'd mention:
Dictatus Papae: I'm not sure how it'd play out, but it gave me some interesting thoughts about running a power struggle set in or centered around the Medieval Church. Definitely not going to be everyone's cup of Sanka, but well worth the free download.
Roguelike: A game inspired by many of the early-80s "roguelike" games out that were (and still are) out there. Very interesting to compare it to the RPG Pundit's Forward...to Adventure!, which has similar influences, but came out quite a bit differently.
I love sites like 1KM1KT--in a way, it's like combing over someone's webpage for their homebrew campaign. You might find some things that'll make you groan, but a lot of time it's worth it for not only finding the gems that are out there, but for seeing things from a new angle.