I prefer unlicensed themes in general. Things that are badass like Sorcerer or something like that. If a game is great (Whirlwind, Fish Tales) and the theme is not 100% horrible it doesn't matter.
With the Alice Cooper Pinball being announced by Spooky I am now faced with a pin whose theme I totally love, but am worried because it better be a great game to live up to the theme.