This is not top, but simply a list of characters looking at which we immediately learn from what universe it is.
Below are the characters who in my opinion personify Warcraft.
1.Kel'thuzad
2.Rexxar
3.Thrall
4.Illidan Stormage
5.Deathwing
6.Sylvanas Windrunner
7.Malfurion Stormage
8.Gul'dan
9.Medivh
10.Legion - Sargeras,Archimonde,Kil'jaeden,Mannoroth.(it's hard not to mention someone)
11.Varian Wrynn
12.Grommash Hellscream
13.Lich-King(all:Bolvar, Arthas,Ner'zhul)
14.Uther Lightbringer
15.Tirion Fordring
16.Cairne Bloodhoof
17.Garrosh Hellscream
18.Khadgar
19. Prophet Velen
20. Jaina Proudmoore
Also recognizable characters are:
Tyrande Whisperwind, Blackhand Destroyer, distinctive from other universes Pandaren race, Samuro and many other heroes we love.