Like both Druid and Ranger for new classes.
And here's a couple more just to mix it up a bit -
Class - Warlock
Skill-tree -
Pyromancer - Fire based DPS
Cryomancer - Frost based DPS
Elementalist - Nature based CC / DPS (mainly AOE)
Class - Necromancer
Skill-tree -
Blood Magic - (similar to siphon)
Summoner - Raise 'temporary' un-dead minions
Life Transfer - AOE health drains into group heals