Click to embiggen.

Solutions after the jump.


From top left to bottom right, images taken from following sources:

1. Space Wolves
2. Dark Angels
3. Blood Angels
4. Ultramarines
5. White Scars
6. Black Templars
7. Imperial Fists
8. Raven Guard
9. Grey Knights
10. Minotaurs
11. Carcharodons
12. Mantis Warriors
13. Crimson Fists
14. Legion of the Damned / Firehawks
15. Iron Hands
16. Flesh Eaters
17. Black Dragons
18. Deathwing
19. Rainbow Warriors
20. Flame Falcons
21. Lamenters
22. Storm Wardens
23. Mentors / Mentor Legion
24. Salamanders

Thanks for reading!