Sci-Fi and futuristic, but I try to stray from somewhat generic looking ships/bases and do something new. I mix it up between a darker ALIENS style of building and a more retro, jetsons-ish style. Landscaping can be fun too, but can be tedious sometimes. However, for some reason, I just don't do much in the way of building castles. It's not that they dont appeal to me, it's just not my style.