"The truth is..."
You know what's great about rewatching movies? You notice things you didn't the first time around because you were too distracted by how awesome the movie was. We all know how kick-ass the suits are. Did you catch how they evolved from film to film?
So we all remember that Tony was working under pressure when he built the Mark I. It was cobbled together in secret, from parts that were never intended to be used this way. The fact that he was able to build it complete with functional flamethrowers is really incredible.
But of course, even though the Mark I was impressive, nothing can top the unrivaled awesomeness that was seeing the Mark III in action for the first time. Hello rocket launchers in the forearm and shoulders. Plus added flexibility in all the joints, and better flight control. The red and gold paint aren't exactly subtle, but it's exactly what we all were waiting for.
This was the first suit to feature a triangular unibeam, because it featured the new arc reactor. The armor also had flare pods on the hips that Tony used to avoid heat-seeking missiles.
"Autonomous Prehensile Propulsion Suit test, initialize sequence." Yeah, my first response when I heard that in theaters was... "huh"? I'm glad we got to see the suit in action! The control Tony had during the above fight scene was an amazing step up from the first movie, the repulsors and the unibeam still packed the same explosive punch.
This suit got destroyed pretty early on in Age of Ultron, but first we got to see the anti-armor tank missile and the new infra-red scanner in action. Super useful toys right there.
Mark 44 aka Veronica aka "The Hulkbuster"
Yeah, this suit has three names. Probably because it does everything the other suits do, just way more. It's got enhanced strength and durability, plus a grappling hook to take down the powerful and out-of-control Hulk.
Tony Stark makes some cool gadgets.
So [spoiler alert] at the end of Age of Ultron it seemed like Tony was giving up on his superhero side gig. Granted, it also seemed like he blew up all his suits at the end of Iron Man 3 and was throwing in the towel. So, he's probably going to come back with an even better suit in the next movie. What other cool tech should he add?