Hank Pym AKA Antman AKA Goliath AKA Yellowjacket AKA Giantman AKA The Wasp
inventor of pym particles, substance which allows the subject to shrink to infinitesimal sizes or grow beyond the very boundries of reality as we understand it.
long history of mental issues, built a robot with his mind (ultron specifically) aforementioned robot has a death count in the trillions and daddy issues like you wouldn't believe.
he's remembered more for smacking his wife during a mental breakdown (and I feel I should mention that rather than getting him help she convinced him to marry her DURING this mental breakdown) than for having built arguably the most successful killing machine in the history of all mankind.
Scot Lang, also Antman, stole the antman suit from Pym to save his daughter who'd been kidnapped by Lang's old criminal associates, he tried to return it but Pym liked the cut of his jib and insisted he remain on as Antman.
Bill Foster, second giantman, fourth goliath. Pym's lab assistant at one point. Helped Pym figure out how to get back to normal after he screwed up and got stuck at 10 feet tall. Got killed during civil war for cheap shock value. Also Clint Barton AKA Hawkeye was goliath for a brief period.
Eric O'Grady "Irredeemable" antman, a lewd pervert and general asshole who wound up with an advanced Antman prototype because shenanigans. One of the more entertaining reads out there and a fun hero once his character development kicks in.