In my quest to make GURPS a bit more playable for people who aren't crazy and read its copious amounts of rules, and to supplement my own GM screen, I went through and collected most of the major rules of GURPS into a handy little compendium. By getting just the rules, it collects the actual stuff needed to play into about 5 pages (skipping all the character generation stuff and rules attached to that, with the expectation that a player will make their own reference sheet for things that effect them).
Still tweaking, formatting, and adding to it, but there's the sheet as it presently is
Page 1 is basics of play: odds of 3d6 based success, the different types of tests, and when to roll.
Page 2 is combat basics, the turn order, and so on
Page 3 is rules for injury and recovery
Page 4 and 5 are further special situations, including rules for shooting things in cover, size/range/speed tables, rate of fire bonuses, and hit locations.