I have crossover dreams.
There was this one that crosses over the characters & areas of American McGee's Alice with Serious Sam II.
Predominantly this year, my game dreams involve replacing the cast of any game of any genre with characters from TellTale games, like Sam & Max: Bioshock, Oblivion, Arkham Asylum, you name it. & if the game doesn't have a lot of shooting or sword slinging, it's usually Strong Bad & Homestar.