My knowledge on the Old Republic is limited and my lack of knowledge on the NJO is second to none so this will only be Disney canon. With this let's go:
0: Rey (because of her Mary Sue powers)
1: Anakin Skywalker
2: Mace Windu
3: Yoda
4: Kenobi
5: Shaak Ti
6: Kit Fisto
7: Kai Adi Mundi
8: Ahsoka Tano
9: Luke Skywalker
10: Master Plo
Because A: this is canon B: he never even fought Darth Vader, rather he fought Darth Jobber (anyone who reads the OT comics would see Vader being challenged and threatened in ways he shouldn't have proving he is much weaker then before) who held back he'l he barley tried and still had the upper hand on him, he only lost because Luke caught him off guard with his Dark Side Berserker Rage which made I'm significantly faster and stronger; oh and Vader wanted Luke to kill him and turn to the Dark Side. And C: at the peak of his power, he can't can't even beat Rey https://youtu.be/zpzZGjr90Pw even freaking Kylo Ren can beat Rey, and he beat a more powerful version of Rey.
0: Rey (because of her Mary Sue powers)
1: Anakin Skywalker
2: Mace Windu
3: Yoda
4: Kenobi
5: Shaak Ti
6: Kit Fisto
7: Kai Adi Mundi
8: Ahsoka Tano
9: Luke Skywalker
10: Master Plo