This coin flipper app has great graphics, realistic physics and... many coins to choose from.
Coin flipper 3D uses an advanced physics engine to simulate coin motion, to detect collisions, and to produce realistic collision sounds. The app also uses the phone's sensors (if available) to determine the gravity vector in order to produce even more realistic output.
Coin Flipper 3D can also be found as part of Gamer's Army Knife, an app comprising a set of useful tools for various various board, party and sports games.