"What class should I play?" is a pretty common question on the forums and in-game, as players try to find what fits them the best. "Play what you like best" is a pretty typical response.
To help someone decide, I've made two flow charts, the first uses the roles to take you down to a class and the second takes the attack type of a class to narrow it down to a class. I've arbitrarily color coded Tanks as gray, healers as light blue, rogues as dark blue, and mages as yellow.