The game I just started GMing for the wife.
Ruleset - D20 Modern, Future, Apocolypse, Cyberscape, Original Psi handbooks, and a smattering of advanced classes that I wrote, found online and borrowed from Urban Arcana (all Psi classes, I wanted one for each base class). I also use / will use a number of d20 monster books (notably goodman games dinosaur planet dinos). I'm also using the gestalt rules from UA.
Setting politically is strait from Space Master 1st edition, houses and politics. There has been some genetic drift due to the long history and problems of the race (using the mutation rules from Apoc there, with a very limited choice of mutations), cybernetics are accepted (Cyberscape), Psi exist, and so do spaceships and mecha. There is also a Jedi like order running around - just using some special feats, access to a lasersword (the only PL8 around, the setting is pretty much PL 7), and the psi advanced classes. PC robots would be allowed, but no one has wante to play them.
As the PCs explore out on the fringe, I'll pull creatures out of various d20 monster books to populate alien planets.