Database numbers
Data I've gathered personally:
Horde:
Out of 7000+ people:
Overall:
- Druid 9%
- Hunter 13%
- Mage 10%
- Priest 10%
- Rogue 10%
- Warlock 8%
- Warrior 14%
- Paladin 11%
- Shaman 11%
60:
- Druid 10%
- Hunter 13%
- Mage 11%
- Priest 10%
- Rogue 6%
- Warlock 7%
- Warrior 13%
- Paladin 15%
- Shaman 11%
Alliance:
Out of 4000+ characters:
Overall:
- Druid 10%
- Hunter 12%
- Mage 8%
- Priest 10%
- Rogue 9%
- Warlock 7%
- Warrior 16%
- Paladin 17%
- Shaman 6%
60:
- Druid 8%
- Hunter 13%
- Mage 7%
- Priest 6%
- Rogue 6%
- Warlock 6%
- Warrior 18%
- Paladin 24%
- Shaman 7%
Most played Horde race : Blood Elf 23% Overall. Undead and Orc on a tie at 24% at 60
Most played Alliance race : Human 43% (56% at level 60)
Obviously, horde numbers are more accurate as I've processed more people... but it's a good aproximation.