No need to be rude here. Anyway I guess they did a pretty bad job at explaining. The fact is that there is not just one that is "best" because it really depends on what you want to do and how you want to do it. You must also realize that you actually get to play 2 vocations at the same time eventually so that makes it even harder to tell you what is the "best".
I will do my best to give you an example:
The absolute top damage dealing single vocations:
Ninja: Melee/Single Target < this is not always the case though as soul is a finite resource for ninja, once it runs out other vocations may deal higher dps.
Leviathan?: Melee/Aoe < not actually sure about this one but in theory it should be
Sharpshooter: Range/Single Target < assuming the Sharpshooter is not moving (walking)...
Pyromancer: Range/Aoe < assuming lots of targets... otherwise there are better options.
The absolute best single vocation for survival in theory should be:
Barbarian: Melee (because it is meant to be a tankier vocation)
The problem is that Priest is able to heal quite a bit so once you rebirth, Priest becomes a better option. (You can go barbarian/priest but I've heard its quite boring)