The oddly named "Silverfish" aquarium—isn't a silverfish aquarium a bookcase?—from Octopus Studios has six orbs connected by tubes, the better to let your fish reconfigure their own habitat while gargling the theme to The Jeffersons. Each aquarium is made-to-order for $3,400 minus gravel and fish. (Freshwater suggested.)
While the manufacturer says it's not much more difficult to clean than a standard rectangular tank, I think we all know that's a bit of understatement. Still, I like it a lot—although I think I'd like it a lot more if it had a more attractive base instead of something that looks like a TV stand from Wal-Mart.