You are on the wrong forum indeed... but I'd also consider beastmaster, they're very good at soloing bosses.
I havent gotten to level 50 yet though, so I can't say for certain how it is then... But I took my lvl 36 DPS priest (with max oratio and credo, rank 1 adoramus, rank 3 RoG, rank 3 renovatio, rank 1 heal and HH) to kill leviathan. The fight took about 7 and a half minutes. Then I took my lvl 41 beastmaster, stripped him from his pants gloves and shoes to make up for the level difference (I'm thinking it probably did a little more than make up for it) and tried again. The bear killed him in under 6 minutes. At the same time, the bear felt much safer, never being threatened in the least, while the priest I had to pay attention to make sure my heals were up all the time and while I wasn't really in danger of dying, the threat was much nearer than for the bear. Also, the bear turns into a tiger and just runs straight to the boss without any problems. The priest without a speed pot can walk and heal himself, but gets hit a lot more, possibly by slows/tangles... which is just annoying. And finally the bear takes less damage, therefore his equip doesn't deteriorate as fast.
Just to note, I tried to compensate for the level difference by taking off half my equip, but the fight felt basically the same as when I did this with my bear around lvl 35 (was never threatened there either). I'm just not entirely certain if the killspeed is accurate.
Sorc might be best, but I guess it all depends on how well they can tank a boss and adds by themselves. My sorc isn't really high level enough to try this yet unfortunately, mostly because I went for my DPS skills before getting healing ones.
edit: Oh yeah, my bear is pure tank spec, no bear form...
Edited by Finraziel, 05 July 2013 - 11:59 PM.