Well, given that the Internet has the most comprehensive index of information about comic books and comic book characters ever created – some call it “Wikipedia” – I searched for this.
Per Comics Lore I can only find that Black Widow slept with, in the comics, Iron Man and Daredevil. Where is the comic book evidence that Black Widow slept with 2. Thor, 3. Hawkeye, 4. Bruce Banner (not Hulk because get your mind out of the damn gutter already), 5. Captain America?
Where is this four out of six number coming from? Space?
http://community.comicbookresources.com/archive/index.php/t-824.html
Iron Man: Tony Stark is the #1 slut of the Avengers, with a list that includes no less than Sunset Bain, Meredith McCall(?), Madame Masque, Marriane Rodgers, Bethany Cabe, Kathy Dare, Veronica Benning, Black Widow, Lt. Colonel Yelena Bremment, Mantis/Space Phantom, Pepper Potts, Countess De La Spiroza, Calista Hancock, Rumiko Fujikawa, She-Hulk, Emma Frost, Jessica Drew, Gamora, and Maria Hill. Nicole and Sheila, from Marvel Comics Presents. Plus Wasp and Tigra are speculated, but unconfirmed, too. (12+, and that’s a conservative estimate)
Vs
Black Widow: Red Guardian II, Hawkeye, Daredevil, Iron Man, Bucky, and some guy in her Marvel Fanfare story (Michael Corcoran.) She also dated Hercules, and he has listed her among his past conquests. (5+)
So, there ya go.
(Oh, I see, he is bitter because Black Widow did sleep with Hawkeye, but maybe not the movie one.)