I have to agree with Gormourn, I choose to not go ret with my paladin not only because I prefer tanking, but also because I am good at it and when a group doesn't have a solid tank the group will fail, and I hate wiping. I also know that if we wipe it's usually my fault, the reason this makes me feel better is because if we fail I can blame myself instead of being pissed off at the shitty tank. Sure it gives me the burden of having the pressure on my shoulders, but I can just tank that too, lol.
I'm not pissing on support roles, DPS you guys are valuable, I mean I can't tank forever, which means mobs and bosses need to be DPSed down fast, but I've also had the unfortunate burden of carrying DPS through instances. Damage meter doesn't lie, when Tank is at the top there's a problem with your DPS... lol.
This is why I prefer to be in one of the main roles of a group, I like feeling useful and valuable. To the Good DPS out there : don't be offended, I've been in a few groups where I wasn't out-dpsing the DPS and I'm very greatful to you guys!