Hmm, outside of fantasy pieces, such as the Liberty Bell (nice one GorillaMan), Abe Lincoln's pipe, Nancy Reagan's skull etc.

I'd go with glass knives, a super nice bong, or a volcano.

Now if neither weed nor money were limiting factors, i'd go with a nice coney J. The versatility would be great, and that feeling after rolling the first J of some good bud right after you just bought a zip is priceless.