Ive recently been clicking and scrolling around the various miniatures systems, as I am a complete newbie and have never before played one. I had hoped that Tannhauser would be my go-to skirmish combat system to dip my feet into, but as many thought, it disappointed.

Im looking for a skirmish-level combat system that takes place largely in structures/buildings, but has the possibility of more open terrain. Ive looked around at making my own Space Hulk set, Necromunda, Hybrid, even Frontiers (terribly written rules and all). I dont mind some complexity to represent squad and platoon tactics, but hopefully the combat and movement systems are relatively streamlined (but not to the point of absurdity!!) I dont particularly want to paint miniatures, but I could always get painted ones locally or on Ebay, so its no great limitation. Maybe 8-24 miniatures per side or so. I prefer sci-fi, and ranged + close combat, complete with cover/concealment, overwatch, etc. Like the idea of CPs used in Space Hulk to represent "interrupt" actions on your opponents' turn, also like the card-driven mechanism of Frontiers (but it seems too simplistic?) -- but Im getting WAY too specific -- fantasy theme or whatever would be fine if the mechanics were great!

Help!!