I was planning on sci-fi next actually. I still have more pieces to add to this pack first, though. If there are some pieces you think would go well with any of the packs, let me know.
Well I can think of plenty of models to make or sets. One would be a Mountain Valley with mountains and rocks and some stuff for a lake such as a boat and stuff that would go with camping. And that would also allow you to make caves and such or plan your map if you want to say map a world. Another one would be a side scrolling set which I don't think I've seen. Alien landscape set, Alien city set, Planet set, Gun set, underground base set, city set, crystal set, superhero set, grave set, Sci-fI building interior set, Egyptian tomb set, Egyptian set, Space Dock set, Interior space ship set. I have lots more ideas but that would have to come at a later time or something I might try myself. You most likely won't have time to do all of this.