What crossovers would you make?

Total War + Civ V

Fallout V(VVVVV)
Prison Architect: Space Program

Unreal Floor (well, KF was originally an UT2004 mod);
Prince of Terraria trilogy: The Dirt of Time, Wood Within, The Two Twins;
Spyro + Touhou (or other danmaku);
Left 4 Magicka (Just would be awesome to have an FPS game, in which we slaughter the zombies with magic, instead of guns);
Audio Hazard (Hell Yeah, shoot those blocks too!)

Pay4Dead

Xbox 4

DukePokeNukem