Mythras (BRP) Space Opera rules, character generation is easy and very similar to Call of Cthulhu. Tasks are skill % roll under on d100; has a nice extended conflict rules for "social combat", and other situations. Has rules and examples for characters, spacecraft, worlds, vehicles, organizations, and aliens. Recommend getting the free pre-gen characters pdf download from the Frostbyte books site, as well as the free RQ6 Firearms pdf from The Design Mechanism site.
A very solid set of rules, only a couple of minor quibbles, nothing that would affect game play. It is generic, with a good coverage of sci-fi themes.