I take no credit for these, but some of them were pretty hilarious.. so I fully intend to use them in-game with my friends. Still, if you have any of your own, feel free to share them.
From Reddit user "Rezzag".
Q: How many Rogues does it take to change a lightbulb?
A: 100. 1 to change it, and 99 to rage on the forums about how they do it better.
Q: What do Rogues and noobs have in common?
A: They both pick locks.
Q: How many Rogues does it take to kill a Pally?
A: 2. 1 to get him low, and the other to wait for him at the Inn.
Yo mama so fat it takes 4 people to summon her.
From Reddit user "Ganky".
Being a Mage is like being Irish. You’re always either fighting or drinking.
Your momma’s so fat, when a Rogue shadow-stepped her, he got a loading screen.
From Reddit User "BuddyFriendGuy".
Q: What do you call a Druid in tree form DPS’ing?
A: A combat log.