Which Profession Should I Roll?

So, I recently took about a year hiatus from the game and I was thinking I'd like to get back in practice before buying PoF. I've only ever leveled one character before and that was my Guardian > Dragon Hunter. I did do a little bit of HoT, but never accomplished much there.

That being said, I think rerolling and relearning the game and enjoying things slowly would be the best way to get back into Guild Wars. I'd really like to play a class that's got good mobility and an aggressive play style. However, to me, it looks like every class can be this way? What's your take on it? Thanks in advance for any advice you can offer!

Yes, any class can be played like that. And in fact usually should, in open world PvE.

So you might consider something that is the antithesis of a tanky-healy-bruiser guardian just to switch it up. That might be mesmer or a melee ele (sword weaver or d/d ele for example.)