For myself (a sorcerer) I like Flap Jack and Ribbit.

Flap Jack is great for farming mobs (places like the tombs, or tower) because with his high health & mana regen, you save a fortune on potions.

Ribbit is great for fighting bosses because of the 40% crit proc. Lots of critical hits cause major damage, especially with Lightning Bolt skill which gives 250% damage on a critical hit.