My standouts:
Havoc DH
Guardian Druid
Prot Paladin
Retri Paladin
Outlaw Rogue
Prot Warrior
So I think my top 3 is:
1. Outlaw Rogue
2. Retri Paladin
3. Prot Warrior.
But rest that I mention is very close. I'm pretty sure all of them will become my default transmog for long time.