Best dungeons are the same no matter what your school.
Level 25: Pagoda of Harmony/Hollow Mountain Level 30: Aquila (Zeus) - best gear* Level 40: Barkingham Palace Level 60: Waterworks - best gear* Level 60: Zigazag/House of Scales Level 60: Tower of the Helephant - best ring/athame* Level 70: Aquila (Poseidon) Level 90: Aquila (Hades) Level 99: Morganathe (Khrysalis final) - best ring/athame* Level 100: Darkmoor - best gear*
Then there are the Archmage and Exalted one-shot duels. You can get Archmage single-shot duels from Meowarity in Marleybone and other end-world bosses throughout the Spiral, or in the Crowns shop.
Skeleton Key bosses are another, incredible source for gear. Wooden keys open doors up through about level 40. Stone keys work in midlevels (60-90?) and Gold keys open the highest level bosses. The key bosses are intense cheaters, and so are the one-shot duel bosses. Be prepared before you attempt them.
Also know that the crafted gear in levels 56-86 is very good if you can't or don't want to farm hard dungeons repeatedly.
There are fan sites that will guide you through all these gear options plus provide battle strategies. I recommend Dualist101 for gear guides and an overview of the dungeon. Mercenaries for Hire give detailed battle plans for the tough bosses.
*Best gear means that it's generally acknowledged as the very best combination of stats for that level of wizard. At level 90, there are secret bosses in Aquila Zeus & Hades dungeons that drop a ring & athame that many wizards are still using at level 120. Morganathe also drops a nice set at level 99.