I am a big enthusiast of chess variants, and here are my favorites: English Progressive Chess Magnetic Chess Knight-Relay Chess Grand Chess Avalanche Chess Glinski Hexagonal Chess Fortress Chess
I've also developed an affinity for Ice Chess since it was added.
(hide) If you want to find an opponent with similar playing skills to your own look in the Ratings page of the type of game you want and find a player with a similar BKR. (pauloaguia) (show all tips)