Here are all the good primarchs that still work for the Empress:

1. Roberta Guilliman

2. Sanguinius

3. Lioness El'jonson

4. Regalia Dorn

5. Venus

6. Laya Russ

7. Jaghatai Khan

8. Ferra Manus

9. Corvus Corax

Here are all the evil daemon/traitor primarchs that turned to worship the Chaos gods and follow Horus as their leader:

10. Horus Lupercal

11. Angron

12. Magnus

13. Morticia

14. Fulgrim

15. Kassandra Cruze

16. Lorea Aurelian

17. Perturabo

18. Alpharius and Omegon (Twins, just imagine two people)

19. Moxxie's Mother (Sad that she doesn't have a name)

Friends

20. The Secret Saturdays

(New harem members on the way!)