There's also the Twink-itus, where you level up to x9 level and twink the crap out of them.

Also, did you know you're only allowed to create a max of 50 characters per account.

Meaning if you created 50 character in 5 servers, you can't make 51st character on a 6th server.

And there's the Level-itus.

Account 1: 70 Pally, 70 Rogue, 70 Shaman, 60 Mage, 39 Rogue, 39 Hunter, 29 Warlock, 20 Hunter, 14 Hunter
Account 2: 70 Priest, 70 Shaman, 60 Mage, 36 Paladin, 32 Druid, 29 Mage, 29 Warlock, 16 Hunter, 14 Rogue, 10 Warlock
Account 3: 70 Paladin, 39 Shaman, 20 Mage, 18 Druid, 17 Warlock
Account 4: 70 Warrior, 70 Shaman