Oh dear, what can one say about Gatecrasher? It's certainly one of the most entertaining games to read. Lucas's humor is a special treat.
The setting is our solar system in the 24th century, some two centuries after Magic returned, and three centuries after we'd colonized other planets and moons. Magic has made a strange hash of everything we've known about - physical laws don't always work, especially on Earth, and fantasy races, long thought to be nonsense, have re-appeared. But some folk still prefer space ships and lasers to teleportation and fireballs, so it's an anything goes kind of solar system. Anything, so long as it's fun, that is.
This is one of the "crunchier" implementations of Fudge, with lots of toys and options for the game master who loves playing with the universe. Complete in one book, it contains its own set of modified Fudge core rules as well as a well detailed setting and bestiary.