There is no 'best' class, if you ask 4 people, you'll get 4^4 answers
It depends on your gameplay and preferences.
Best survivor is
2. Hard to decide, warrior and mage have the highest Single damage, cleric and mage have better party damage
Also hard to decide, warrior can be a good tank, but cleric with heal and intervention is sometimes even better.
Long story short, if you want an easy character for the first play through, I'll recommend cleric (paladin, joining warrior guild) or warrior, Both meele.
More complicated is cleric (child of faith build as supporter) or a Mage (summoner build is the easiest to play)
Most complicated, but it depends on your preferences, is the meele rogue, you have to be more careful with him, does a lot of damage but dies very easily if you're too careless.