I have been messing around with the Delta Dice by Diamond Jim Tyler. Basically you show two dice and the magician always rolls a higher number than the spectator. They take your and you gab another. The spectator still loses! They take your die and you take the original "bad" die from the beginning and you still win!
It's obvious that the dice are mispipped but it still doesn't feel possible that each die wins the other in Rock, Paper Scissors fashion.
Of course you want to look at Fast and Loose as well as pricking the garter. These are fun. Paul Vigil has a good version of fast an loose he teaches on his Penguin Live lecture.
You probably want to look into the books of Diamond Jim Tyler he has a bunch of great scams that are fun to watch and play along with.
Other fun presentations are things like cutting to the aces
see, and the 10 card poker deal.