Profession's for PvE
What I have found about this game, more so than MMOs, is that your own personal play-style really does matter. I main a thief, but I did try the other classes and can see me rolling alts in the future (something I never do!). Try them out! I do not think there is any one class that shines above another.
Concentrate skillpoints into shadow-arts and acrobatics for leveling. Together with signet of malice and assasain’s reward, survivability will not be a problem anymore with pretty-much any weapon you prefer (SB ftw).
Warrior is good for everything right now, but I got bored with mine for other reasons. Ranger is excellent for DE farming and tagging mobs for when you want to grind for cash and loot, or for single-target action. You can either go for a pet-centric build or a build that relies very little on your pet. I haven’t tried my thief or ranger in dungeons yet and don’t plan to, but I hear both do well (although thief has a learning curve).
All three light armor classes are busted right now as far as I’m concerned, but if you really want one I suggest mesmer. I hear that they are hard to level due to comparatively low damage output, but are a great support class and I think they have some good aoe attacks (see end-game farming).
My first toon was a Thief, fun class, very tactical, but at level 20 realised it was going to be too squishy for mainly solo PvE. I think the class works better when playing with a group.
I’m playing a ranger now (level 62), and really liking it. Lots of options for weapons, pets, etc. for different play styles.
I don’t think any class really stands above others, or any class is below others. Every class can be useful at everything if they can play well.