Out of all of the armors that have appeared in the Iron Man comics, the Silver Centurion is one of my all-time favorites. Why? Just take a gander at it.
The most obvious distinction is its color scheme. This is one of the few main armors that doesn't follow the red and gold coloring that Tony Stark preferred. The choice of crimson and silver by whoever designed the suit was a smart choice and the overall design really makes the Silver Centurion stand on its own.
The Silver Centurion made its inaugural appearance in Iron Man #200 which featured the climatic battle between Iron Man and Obadiah Stane (in his Iron Monger armor) and was the culmination of the long story arc that existed between Stark and Stane since the latter stole Stark International and forced Tony to relapse back into alcoholism and become homeless.
Tony would continue to wear the Silver Centurion until issue #230 when it was destroyed by Firepower, a very large and very powerful battlesuit, during the Armor Wars. What's interesting here is that he actually publicly "fired" Iron Man (remember, unlike the MCU, the world didn't know that Tony was Iron Man) and then faked his death during his battle against Firepower. He accomplished the latter by simply removing the suit, filling it with blood packs, then sending the reassembled suit at Firepower to be destroyed. In the next issue, Tony built a new armor and used it to stop Firepower, who was just being a dick by that point by attacking Stark Enterprise properties.