I really like architectural cakes that play with different heights and dimensions. I'm really liking the cakes on the bottom row (with the exception of the funky brown one).

Maybe the one on the bottom left, but in brown instead of black? Or maybe in white chocolate frosting with gold pearls and piping?

I also like the bottom right, second to the left as well. It's tall and skinny which might work better with the tall atrium space.