Luke, Revan, Exile, kun, sadow,
Luke because he managed to do the ''impossible'' Less training and then getting a sith lord to the lihgt path again..............
Revan because he had gne to the outer rim on his own.................to fight the true enemy and if you would play dark side he still had gone there to protect even the republic.......... (as a sith lord )
exile because she could become a jedi (again) and because she could (if she wanted it or not) make wounds and conections trough the force...
Kun because he almost managed to destro the republic/jedi order...............and almost had the evil sith empire built up again................
Sadow...........because he was the best sith algemist (spelling ).......