For me there's only one profession above all others: Monk. For some unknown reason I really enjoy and excel at playing a healer or protector when in a team.
I have tried every profession multiple times:
Warrior - ok... but I don't really like to play them
Ranger - not me... no, I get too sentimental with my pet dying
Elementalist - nope... I tend to die before I can cast a spell
Assassin - same problem as with warriors
Ritualist - no... I could maybe play rit, but I still like monks the best
Mesmer - no, no and no... mesmer is so much not me. I cannot play a mesmer at all.
Monk - here's the winner! Out of my 18 chars, only 6 are primary monks

And the rest are just secondary monks who can actually function as a full-time healer or at least a healer-aid.