From the time he was introduced in what was originally meant to be a one-shot story in Tales to Astonish ("The Man in the Ant Hill") through his bizarre career as the miniscule ant-man with his partner the Wasp, and his even more bizarre career as the somewhat clumsy Giant-Man (not to mention Goliath and Yellowjacket), through his various stints with The Avengers, Henry "Hank" Pym has been one of the most fascinating characters in the entire Marvel Universe. Read about him, his adventures, his neuroses, his breakdowns [and stories of particular interest] here:
A MAJOR PIECE ON HENRY PYM AND HIS VARIOUS INCARNATIONS WILL BE POSTED VERY SHORTLY.