Warcosm is a good set of light spaceship combat rules. There is a thin setting attached that you can use but largely this game is meant as a framework for you to create your own universe to play in which makes it ideal for any spaceship minis that you might have lying around. The rules also include a well laid out random scenario generator so you can just roll up the scenario instead of creating one yourself which I think is a nice touch. The only complaint that I have is that some of the rules were a little unclear at first glance but even these were fairly minor. If you are looking for a fun, fast, and light space combat game then I'd definitely recommend giving this one a try!
[4 of 5 Stars!]