Play what you enjoy the most or you'll be constantly disappointed. I speak from experience...in a previous MMORPG I decided at one point to play a certain class "for my guild" because that's what we needed for our progression raid team, and I was not happy because I wasn't playing the class I actually wanted to play. It felt good helping the guild, but not good enough to outweigh the boredom of playing a class I didn't enjoy.