The Classic Red & Gold Armor

Late 1960s to 1985. This armor had some variations, which included the nose and the roller skates (Iron Man the first on roller-blades). This armor has logged more issues than any other Iron Man armor. From the power pods to the round ear pieces, this armor remains among the greatest armors. Appeared for the last time as the primary armor in Iron Man #199.

The Silver & Red Armor

First appeared in West Coast Avengers Vol. 2, No.1. Appeared a month later in Iron Man #200. Also appeared in Secret Wars #5 around the same time, so the first appearance in disputed. Appeared for the last time as the primary armor in Iron Man #232. This armor introduced the pulse bolts and chameleon armor mode.

Red & Gold Armor

First appeared in Iron Man #231. This armor introduces the electric shield among other gadgets. John Romita Jr. made the armor bulky and introduced large boots. Appeared for the last time as the primary armor in Iron Man #281.

Undersea Armor

First appeared in Iron Man #218. This armor is actually two separate armors. The outer shell is for the water pressure and the inner armor is for ejecting for a quick rise to the surface.

Space Armor (#14C)

First Appeared in Iron Man #142. Tony had special prototype armors that he had been working on stored in his New York Stark International property. Designed to operate for extended periods beyond the earth's atmosphere. The armor allowed Tony to jet off into space quickly. The command circuitry is more sensitive than his other armors. Also appears in Iron Man #143-144.

Iron Knight

First appeared in Avengers Vol. 3, #1-3. Iron Man was under the control of Morgan La Fey until he came to his senses and help the others escape that medieval world. Have not seen the armor since the Avengers series.

Heroes Reborn

First appeared in Iron Man Vol. 2, No.1. When the rest of the Marvel went up against the villainy of Onslaught, Teen Tony Iron Man sacrificed his life with other heroes to end the terror. Casts into another universe called "Heroes Reborn", Tony Stark was an adult again, but his ways to his riches was not as noble as his heart. "Reborn" to his noble heart after a life threatening accident, he set on a crusade as the invincible Iron Man to help the world in whatever way possible. Appeared for the last time as the primary armor in Iron Man Vol.2, No.13.

Heroes Return I

First appeared in Iron Man Vol.3, No.1. Having been out of the regular Marvel Universe for over a year, Iron Man returns to the regular Marvel Universe as an adult Tony Stark. With a new outlook on life, Tony decides not to take back his old Stark Enterprises and starts a consulting firm called "Stark Solutions".

Heroes Return Space Armor

First appeared in Iron Man Vol. 3, No.14. Tony just found out that his armor was killing him, but there was this world ending threat that he had to take of. The armor has a special padding to prevent the radiation from killing him. I have not seen it since that issue.