Looking for 15mm/28mm sci fi game

[Parrot]

I am looking for a general idea of some good rule sets in the 15mm 28mm sci fi genre.  I already know of Mantics offerings, 40k and Gates of Antares, but are there any other good ones in 28mm?  As for 15mm I know of Hammer's Slammers, but little else.  In both 15 and 28 I am looking for something with tanks and infantry, in large scale or large skirmish games,  I think 10mm is a bit to small for me right now.  Thank you for any suggestions that you might have!

[NurgleHH]

Victory Decision: SciFi