I'm currently reading through the comic American Vampire and got to thinking that HBO should, just for shits and giggles, make a Boardwalk Empire/True Blood crossover. I'm sure fans would dig the combination of Prohibition Era mafia type dealings meshing with erotic vampire drama.

Hell, throw in a cameo or two from either series and I'm sure the ratings will go up. I don't watch either show, so ruining them both wouldn't bug me. :P