Including all force users:
1. Luke Skywalker.
2. Jacen Solo.
3. Darth Krayt.
4. Kol Skywalker.
5. Raynar Thul (Killek powered).
6. Darth Sidious.
7. Zenoma Sekot.
8. Kyp Durron.
9. Darth Revan.
10. Darth Bane.
11. Marka Ragnos.
12. Darth Nihilus.
13. Exar Kun.
14. Naga Sadow.
15. Simus.
16. Ludo Kressh.
17. Darth Traya.
18. Darth Malak.
19. Darth Sion.
20. Darth Bandon.
Potential to be on the list: Cade Skywalker, Jaina Solo, Nomi or Vima Sunrider, Zayne Carrick, Darth Zannah, Bastilla, Ben Skywalker, Allana Solo, Leia Organa-Solo, Darth Talon, Shado Vao.
Unknowns who could possibly make the list: Adas, Xendor, Ajunta Pall, The Dark Underlord, Tulak Hord, Roan Fell (and potentially Sia), Lord Hoth, Lord Farfalla, Darovit (potentially), Kiel Charney, Freedon Nadd, Quordis, Kaan, Kopekz, Ka'sim, Githany, Seviss Vaa, Darth Nihl, Darth Stryfe, Darth Wylock, Wolf Sazen.
Those who just missed it: Yoda, Ulic-Quel Droma, The Exile, Mace Windu, Anakin Skywalker, Odan-Urr, Vodo-Siosk Bass, Thon, Dooku, Kyle Katarn.
Jedi:
1. Luke Skywalker.
2. Kol Skywalker.
3. Kyp Durron.
4. The Jedi Exile.
5. Kyle Katarn.
6. Yoda.
7. Ulic Quel-Droma.
8. Mace Windu.
9. Vodo Siosk-Bass.
10. Odun-Urr.
Sith:
1. Jacen Solo.
2. Darth Krayt.
3. Darth Sidious.
4. Darth Revan.
5. Darth Bane.
6. Marka Ragnos.
7. Darth Nihilus.
8. Exar Kun.
9. Naga Sadow.
10. Simus.
Don't think I missed anyone.