My parents have a number of puzzles from ELMS Puzzles, Inc. They are a company that makes these beautiful hand made wooden puzzles that are usually quite hard. I took some pictures of the one we're working on right now. It is one of the more challenging puzzles I've ever done because the edges aren't straight. Also, they seem to like to put some pieces in that have a straight edge on them that go in the middle of the puzzle, helping to confuse you more. Oh yes, and there's no picture of what the puzzle will look like, so it is kind of cool waiting to see what the whole thing will look like.

My mom also just mentioned a place called Stave Puzzles, that sounds like another place that does the same kind of thing (with some even crazier looking puzzles).