I agree with Mortal's Class lists but here's a tip:
When my Priest's class was in 9th level, I stupidly switched the class over to a monk. I couldn't fill up the Vine level spell list
So I waited until my character's monk class is up to 17th level then switched over to Warlock class and finished the Vine list (yes it's a bad pun).
------------------
Adam Mage/Warlock