While Etienne Meneau's N°2 and N°4 decanters are a whopping €2,000 apiece, they are inarguably appealing. Don't even try to argue!
As Core77 points out, the "branchier" N°4, when filled with a red wine, looks a bit like blood vessels. It reminds me of the circulatory systems they show at the Bodies exhibits, where latex-filled arterial networks are removed from corpses—or rather, the bodies are removed from around the latex using some indeterminately gruesome method—and hang in the air like primary-colored trees.
Strangely, I bet you could buy a dead body for less than these decanters.