How many Hulks can you name off the top of your head? All save a seasoned Banner-booster probably can't name every single variation on the Emerald Avenger theme, since there are quite a few. Each Hulk may not be a different aspect of Bruce's personality, but most of them are distinctive spinoffs. So without further ado, we present the cavalcade of Banner psychoses!
Bruce's best-known alter ego, on display for audiences everywhere in The Avengers films, is the Savage Hulk. Childish and brutal, he's the archetypal id, smash-first, and then transform back into Bruce to ask questions later Hulk. Among his other fairly well-known personas is Gray Hulk, otherwise known as Joe Fixit. Fixit was a takeoff of the very first iteration, a washed-out gray, who was forced to go green because of printing color consistency issues at the publishing house. The later Gray Hulk—after Bruce and his alter-ego's trial separation in the '80s—literally only comes out at night and exhibits a cunning and manipulative persona.
In addition to his archetypal variances, Bruce also manifests as the Gravage Hulk (a blend of Gray and Savage Hulk), Merged Hulk (a smarter merger of Banner and Hulk), Green Scar (Planet Hulk's evolved and more-potent version), Dark Hulk (his Shanzar-possessed "strange-dimensional" Hulk), Doc Green (another smart Hulk), Kluh (long, Onslaught-related story there) and The Guilt, who unsurprisingly represents Bruce's massive guilt, among others. Technically, Red Hulk, Totally Awesome Hulk, and She-Hulk don't count, because they're other people.