Here are the top 50 Marvel characters, voted for by CBR posters:

1. Spider-Man
2. Captain America (Steve Rodgers)
3. Wolverine
4. Daredevil
5. Thor
6. Hulk (Bruce Banner)
7. Iron Man
8. Doctor Doom
9. Magneto
10. Deadpool
11. Cyclops
12. Doctor Strange
13. Storm
14. Thing
15. Jean Grey
16. Hawkeye (Clint Barton)
17. Black Panther
18. Scarlet Witch
19. She-Hulk
20. Silver Surfer
21. Kitty Pryde
22. Nightcrawler
23. Captain Marvel (Carol Danvers)
24. Rogue
25. Black Widow
26. Punisher
27. Venom
28. Emma Frost
29. Spider-Man (Miles Morales)
30. Gambit
31. Moon Knight
32. Ms. Marvel (Kamala Khan)
33. Vision
34. Mister Fantastic
35. Thanos
36. Winter Soldier
37. Iron Fist
38. X-23
39. Beast
40. Iceman
41. Spider-Woman (Jessica Drew)
42. Loki
43. Ghost Spider/Spider-Gwen/Spider-Woman (Gwen Stacy)
44.(tie) Namor
44.(tie) Psylocke/Captain Britain (Betsy Braddock)
46. Invisible Woman
47. Wasp
48. Human Torch
49. Luke Cage
50. Rocket Racoon

Comments:
Rocket is the most popular Guardian.
Captain America being ahead of Wolverine is due to the MCU.
The Thing has always been the most popular member of the FF, but Doctor Doom is ahead of him.
Magneto is more popular than any X-Man except Wolverine.
Storm is the top female X-Man.
Scarlet Witch is the top female Avenger.
Doctor Doom is the top villain in the Marvel Universe.