Hmmm... These are the levels I reached.
Druid: 80 (My second main, did raids in classic with this guy)
Shaman: 73
Death Knight: 71
Warrior: 70 (My first 70, used for pvp)
Paladin: 63
Mage: 62 (my first main, second 60)
Rogue: 60 (My first 60, then abandoned when friends switched servers)
Huntard: 30
Warlock: 24
Priest: 20
Gotta give every class a chance.
Druid: 41 days, 1 hour, 57 minutes and 39 seconds.
Shaman: 12 days, 1 hour, 24 minutes, 15 seconds.
Paladin: 6 days, 16 hours, 16 minutes, 56 seconds.
Rogue: 21 days, 18 hours, 5 minutes, 17 seconds.
warrior: 26 days, 13 hours, 59 minutes, 33 seconds.
DK: 2 days, 0 hours, 59 minutes, 20 seconds.
other DK: 1 days, 17 hours, 32 minutes, 33 seconds.
mage: 21 days, 13 hours, 32 minutes, 31 seconds.
This gives a grand total of:
121 days, 11 hours, 48 minutes and 4 seconds played on my most played chars. Not including the chaff.
Yup, wasted waaay too much time on this game.