MANguard FTW, but then, I tend to gravitate towards tank classes in general

Male Human Vanguard, body type 1, no regrets whatsoever. That scrawny little guy who looks like he'd fly into the stratosphere from a gust of wind? He's the tank.

Me too'd, especially the part about playing what you like. It just isn't effing worth trying to force yourself to play a class/role that you hate, and everything else being equal (or even nearly-equal), you'll be worse at it than the guy who loves the class/role he's playing. That said, in my opinion/experience (your exact mileage may vary), Guardian is kind of a late-bloomer in the tanking department, not really getting good until 30+. (I've also started a Vanguard, but haven't gotten high enough with him to really be able to compare yet).