I like No Limits http://www.wargamesunlimited.net/nolimits/
Low miniature footprint - in the order of 8-20ish miniatures being a reasonable force.
Sci-fi - I like my guns, dammit.
Bring-your-own-mini friendly - Iíd like it to be perfectly fine to play with a mix of 28mm GW, Hasslefree, Heresy, Reaper, whatever.
Not bolted on to a larger wargame - I donít want something like the kill-team rules for warhammer 40,000. For added Variety Check out Boarding Action.
Be relatively rules lightweight. - Iíll need to convince friends to have a crack at it also.
- Bonus: House Rules Friendly