I’m a great fan of lightweight and free games. I surfed around in the internet and found these:

2d6 Fantasy

Some stats and an easy task resolution: 2d6 + stat modifier. Results are sliding (catastrophe, miscast, delayed success, immediate success or puissant success). Looks like a Barbarians of Lemuria/Talisman/Apocalypse-World-Hack. Check it out at Untimately.
There’s already a nice little hack (which I like even better) on Tales Of The Grotesque (broken link removed).

The Bureau

The Bureau is an Apocalypse-World-Hack by Paul T. with different dice types. Very slim and nicely done. The setting is something like Men in Black & Ghostbusters. Character creation is a bit more free-form which I like a lot. Character traits (which remind me of Lady Blackbird are an incentive to do something interesting in order to get some game resources. Helping and experience also give the game a new twist.
The game was developed for children but I honestly can’t find a reason why I wouldn’t play it with adults.