Captain America
Captain Britain
- Betsy Braddock
- Brian Braddock
Daredevil
- Matt Murdoch (Daredevil)
- Parnival Plunder (Plunderer)
Dr. Strange
- Steven Strange (Dr. Strange)
- Fin Fang Foom
Fantastic Four
- Reed Richards (Mr. Fantastic)
- Sue Storm (Invisible Woman, before marriage)
- Silver Surfer
- Wyatt Wingfoot (star athlete and friend to Johnny Storm)
- Victor Von Doom (Doctor Doom)
- Peter Petruski (Paste-Pot Pete)
Hulk
- Bruce Banner (Hulk)
- Betty Banner (Bruce's one-time wife)
- Brian Banner (Bruce's father)
- Samuel Sterns (Leader)
Iron Man
- Happy Hogan (assistant)
- Pepper Potts (assistant)
Spider-Man
Thor
- Loki Laufeyson (brother of Thor)
- Balder the Brave (companion of Thor)
- Beta Ray Bill (rival to Thor)
X-Men
Other
- Jessica Jones
- Kamala Khan (Ms. Marvel)
- Richard Rider (Nova)
- Wade Winston Wilson (Deadpool)
- Greer Grant (Tigra)
- Blackagar Boltagon (Black Bolt)
- Val Ventura (Flatman)
- Rocket Raccoon (Guardian of the Galaxy)
- Dum Dum Duggan (one of the Howling Commandos)
- Robert Reynlods (Sentinel)
- Lindy Lee (maiden name of Robert Reynolds' wife)
- Carl "Crusher" Creel (The Absorbing Man)
- Mary MacPherran (Titania)
- Adam Austin (Masked Man)
- Robbie Reyes (Ghost Rider)
- Big Bertha
- Dennis Dunphy (Demolition Man)
- Barney Barton (older brother of Clint Barton, Hawkeye)
- Millie the Model (humor comic published by Marvel)
And a lot more…
I barely scratched the surface with this, as there are many more characters with alliterative names. Still, the major ones, a number of secondary characters, and a few "never heard of 'ems" are in there. If anybody sees any glaring omissions, feel free to edit them in.
Why so many?
In a 2006 Q&A, Stan Lee explained why there are so many alliterative names:
"It would be hard for you to believe this, because I seem so perfect: I have the worst memory in the world," Stan said. "So I finally figured out, if I could give somebody a name, where the last name and the first name begin with the same letter, like Peter Parker, Bruce Banner, Matt Murdock, then if I could remember one name, it gave me a clue what the other one was, I knew it would begin with the same letter."