The Defenders were a loosely organized team of fictional characters, mostly but not solely superheroes and for much of their history there was no clear distinction between "official", honorary, and associate members or even allies. Thus, the Defenders had a reputation as being a non-team, a term which was coined in the pages of the comic. All could be considered Defenders.
These are my choices for who I think should play the main members of the non-team along with the issue they first joined The Defenders!
Founders
Johnny Depp as Doctor Strange
Marvel Feature #1 (December, 1971)
Ed Norton as The Incredible Hulk
Marvel Feature #1 (December, 1971)
Zachary Quinto as Namor the Sub-Mariner
Marvel Feature #1 (December, 1971)
Later Members
Isla Fisher as Clea
Marvel Feature #2 (March, 1972)
Doug Jones/Laurence Fishburne as Silver Surfer
Defenders #2 (October, 1972)
Rupert Penry-Jones as Black Knight
Defenders #4 (February, 1973)
Yvonne Strahovski as Valkyrie
Defenders #4 (February, 1973)
Mandy Moore as Namorita
Defenders #5 (April, 1973)
Chris Pine as Hawkeye
Defenders #7 (August, 1973)
Alyson Hannigan as Hellcat
Defenders #44 (February, 1977)
Casey Affleck as Moon Knight
Defenders #47 (May, 1977)
Katherine Heigl as Ms. Marvel
Defenders #57 (March, 1978)
Bret Harrison as Spider-Man
Defenders #61 (July, 1978)
Eva Longoria as Wasp
Defenders #76 (October, 1979)
Djimon Hounsou as Black Panther
Defenders #84 (June, 1980)
Billy Crudup as Beast
Defenders #104 (February, 1982)
David Boreanaz as Wonder Man
Defenders #104 (February, 1982)
Hugh Laurie as Mister Fantastic
Defenders #105 (March, 1982)
Serinda Swan as Scarlet Witch
Defenders #112 (October, 1982)
Michael Rosenbaum as the voice of The Vision
Defenders #112 (October, 1982)
Nathan Fillion as Nighthawk
Defenders #112 (October, 1982)
Patrick Stewart as Professor X
Defenders #15 (September, 1974)
Mark Pellegrino as Son of Satan
Giant-Size Defenders #2 (October, 1974)
Terry Crews as Luke Cage
Defenders #18(December, 1974)
Michael C. Hall as Daredevil
Giant-Size Defenders #3 (January, 1975)
Jeffrey Dean Morgan as The Thing
Defenders #20 (February, 1975)
Patrick Wilson as Yellowjacket
Giant-Size Defenders #4 (April, 1975)
So thats it, let me know what you think in the usual place! Thanks for reading!!!
And if you haven't yet seen them, here are a list of links to my other fan casts!
The Avengers
The Avengers II
The First Avenger: Captain America
Thor
Dark, Mighty and New Avengers
Dead Space
Captain Britain
Fantastic Four
Spider-Man: The Second Trilogy
The First Avenger: Captain America II
Daredevil
Moon Knight
X-Men 4
Doctor Strange
Young Avengers TV Show
New Warriors TV Show
The Inhumans
Alpha Flight
Spider-Man: Sinister Six
The Punisher
West Coast Avengers
The Ultimates
And don't forget to check out my biggest fan cast of 205 Marvel Characters!!!