Here's one of my own most recent chess variant inventions, called Hannibal Chess. It's played on a 10x8 board and has 2 extra pawns and two extra elephant-like pieces per side. At least some people that play like it, and some consider it might be prototypical of whatever might replace chess in terms of popularity some day, if that ever needs to happen:
http://www.chessvariants.com/rules/hannibal-chess
There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.
Hamlet (1.5.167-8), Hamlet to Horatio.