Two things about this one:
First, for the (relatively) low price of $3,675, you can take a trip to zero gravity! I'd take that over an equally priced cruise most any day (although, with some locations the cruise would win).
Second, check out the pictures of Stephen Hawking in zero gravity. He looks quite happy
http://www.gozerog.com/
(and, yes, I know his face doesn't exactly have a lot of versatility in terms of expressions, but nonetheless he seems happy. I know he was really looking forward to the experience.)