I've played GURPS for years, and recently started GMing it (thanks to
Matt Colville). I looked through the various "One Page" GURPS handouts and never could find exactly what I wanted.
So I created
Combat Cheatsheet V4.
EDIT: Updated the link to point to Version 4 of the cheatsheet. Removed the home rules and made it as RAW as possible.
Of course, it includes a bunch of home rules (Initiative, No Major Injuries, Mounted combat, etc.), and not all RAW are included, but you should be able to copy it and edit as needed. The back side is an explanation of the maneuvers, useful for new players to try to understand what each option means, in non-game terms.
I put many of our most frequently used rules onto it, and it has come in very handy.
It is color coded and two sided. I printed out a few copies and laminated them to hand out to the players.