The Greatest Superhero Costume Ever...

....remains the Ultimate Iron Man design by Bryan Hitch. (At least in my opinion.)

The Ultimates by Hitch and writer Mark Millar did many things different from the original Avengers, most notably by amping the negative traits of the original heroes up to 11 and making them Bush administration toadies (except for Thor, who was a tree-hugging New Age wackjob). But where other reboots kept to the core of the character, the Ultimates stripped down every piece of its source materials and kept only the basic aspects intact while opening everything else up to contemporary reinterpretation. A great example of this, and why the Ultimates remains one of my favorite comics of all time, is the Ultimate Iron Man design.

Where traditional Iron Man designs had been more streamlined, to the point where the suit was basically a shiny wetsuit with a robot mask, Hitch's version went the opposite direction, to make Tony Stark's signature creation feel more plausible. While the capabilities of Iron Man were still light years ahead of any current technology, Hitch put so much thought into the design that it felt plausible. Ultimate Iron Man was effectively a wearable fighter jet, wrapping around a human figure and falling just short of obscuring the shape of the man inside. Big grey and silver segments wrapped around Tony's form, while his signature repulsor rays and boot jets went from being small discs on the hands and feet (respectively) to pronounced wrist cannons and big triangular apparatuses. The helmet was similarly retooled, with an alien shape that completely obscured any human expression. When the suit was active, the eye pieces and the chest-mounted unibeam took a blue glow, giving the suit accents of all three primary colors tactically distributed across the gray frame. Even the Ultimate Iron Man suit's disassembly showed remarkable attention to detail, as the assembly and disassembly of the suit was an elaborate operation that required everything from neural ports on Tony's own bare arms to a green fluid inside the armor (that presumably protected Tony from being cooked alive by the powered-up suit).

It's very likely that Bryan Hitch's design helped inspire Adi Granov's version for the Iron Man movie, which kept the "wearable fighter jet" aesthetic but used the scalding red and gold color scheme of the classic Iron Man suits. Unfortunately the Ultimates eventually retired Hitch's design in favor of the movie suit; understandable due to the iconic power of the Marvel movies, but a less interesting visual.