I've tried most specs so far.
Of them all, the one I like least for solo world stuff is Spectre. It isn't bad, I just don't like playing it when I'm solo. I imagine it'll be much more fun in a group setting.
As far as Tanky-ness goes, I think gear probably matters way more than class if you want to solo pve stuff. I've seen people of each new spec do incredible things by themselves in PvE, but they were all in full ascended gear. Saw a spectre practically solo a HoT hero point champion by themselves.(That chak kitten in Auric Basin). I spent most of the fight rezzing myself while he stood in front of it spamming his attacks.