First tried sloopy but couldn't arrange it nicely, so switched to hilltop, and immediately liked it.
I like the natural separations, perfect when you son't like fences. Also I like to leave place for wilderness in the farm, with trees left to grow. With hilltop such wild zones cannot spread too much.
But now at my 4th year I start to lack space, especially for new buildings. I had to sacrifice my wild forest to build a pond :'(, and will never build Slime hutch which is too ugly anyway.