I stop dungeoning around 75 because I get some that are annoying to box as part of the random rotation, depending on the team comp.
75-80 I just do Hellfire Peninsula or Zangarmarsh or Borean Tundra. Takes maybe 2 hours if that?
80-90 Pandaria - mix of treasures and parts of the various zones that are kill/loot quests. I usually do this in something like 4-5 hours total, maybe a little longer.
90-100 - Draenor flying around and getting treasures where they align with the bonus objectives, and also sometimes grabbing a quest if it's just a kill all. Stupid fast, like 2 hours maybe, or 3 if you do the intro instead of just getting a mage to port you.
100-110/111 - Legion Assaults usually I let the team rest and do two assaults and maybe questing
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