Return of Reckoning

Obligatory "level in RvR". Being R31 and only RR9 isn't very fun.

They have removed the rats that were used in the RvR lakes to power level.
There are a few PQ's throughout T2/T3 that are great for XP grinding if that's your thing.
The Skaventide quests in the mid 20's will also net a ton of XP ...