Yall live in the past too much. but i'm just a kid. Shrug.
Knight - Maleki (he is the most creative, innovative knight out there, and as his skills continue to grow and he experiments more, I see him developing beyond the unpredictable dangerous levels he is at)
Seer - Flagg (he was not only excellent at defence, but he was creative and lethal with the combinations of afflictions he created, as well as in his manipulation of puppets and coalesced stones)
Thief - Dreeman (he may have been absolutely non-combatant, but he knew how to train and encourage others to an excellent level. he also roleplayed the life wonderfully)
Sorcerer - Threap (nasty. need I say more?)
Ranger - Ender (same fighting prowress as Pahn, but more creative and mentally frightening with the roleplay)
Bard - none in my lifetime
Loremaster - Kodiak (amazing defence. simply can't be killed if he doesn't want to be. lethal in a team)
Mage - Fistandantilus (or Oriniko, though I never faced him as a knight... either of these because they possess strong defence and unique offense)
Most of my choices aren't based on death tallies, but on their innovation and creativity in fighting. In my opinion, THAT is what makes the best fighter - not who you can kill, but the style in which you do it. They are all people I have encountered, so a much shorter list of options, I suppose.
Written by my hand on the 10th of Eleuthral, in the year 1144.