Churches. Empty Churches.
'Cause they're the only thing I'm any good at it. >:(
Plus, I hate building Interiors, since I'm so terrible, and I hate the fact that most things just look too big. Like, having a 1x1 plate for a Computer Mouse, it just seems too big IMO. I tend to let other people decorate the interiors of my builds, since I'm so concerned that things look oddly sized or are going to turn out ugly.
I guess I'm also not too bad at Houses either, other than the interior thing again.
Landscaping I'm so-so with, but I get bored with it, or I find it looks unnatural or just terrible.
Also, despite the fact that I've allways wanted to do a floating island, I never have. Usually because I don't tend to like the looks of them from below. o;