From the very beginning, Tony Stark was the man that built the Iron Man technology from the ground up. He's the one that has gone through the up and downs, the good the bad, and the right and wrong. He's the man that we think of when we hear the name Iron Man. But, he is not the only one that has donned the Iron Man technology over the years. So, what I have are 6 of the many people that have been Iron Man.
James Rupert "Rhodey" Rhodes
This one, you probably know. Rhodey becomes Iron Man after Tony Stark looses his fortune to Obadiah Stane. Stark succumbs to alcoholism, and Rhodey takes the mantle of Iron Man. He eventually gives up Iron Man after he is injured by Obadiah Stane, but then regains it after Stark's presumed death.
The Iron Man of 3030, Rhodey Stark is named after Tony's close friend James Rhodes and is Tony Stark's biracial granddaughter. She travels to the future to help the Avengers save the Earth from a rogue planet that has been sent from the distant future.
Yes, I know what you are thinking. But, in the story line Bullet Points, Steve Rogers accepts to be bonded in an early form of Iron Man. In this story line, the Captain America project is cancelled because of the assassination of Dr. Abraham Erskine. Steve Rogers is later killed, in which Tony Stark steps up to become Iron Man.
Arno Stark is the 2020 version of Iron Man. Arno is a mercenary of Sunset Bain, and, just like Rhodey Stark, travels back in time to save his family from a bomb. After much confusion, Arno eventually ends up killing Tony Stark.
In the continuity of Earth-3490, Tony Stark is born a woman, Natasha Stark. So, instead of Iron Man, she's Iron Woman. And in this continuity, Steve Rogers and Natasha Stark are even married. And because of the marriage, they are able to avoid the Civil War.
The Iron Man of the story line Marvel 2099, Sonny Frisco, whilst being able to wear a regular Iron Man suit, actually suffers from dwarfism. He becomes a member of the Alchemax corporation team of Avengers.