Though building out the armor required for an Iron Man suit is obviously (some would say imposingly) impressive, re-creating the detailed webbing and lithe nature of Spider-Man's suit is just as incredible a feat. MoonSpider shared the Spider-Man suit he made and it puts all Halloween Spidey costumes to shame.
This is something Tobey Maguire Andrew Garfield Peter Parker would wear.
MoonSpider admits that he didn't actually make the suit himself but he connected all the right and talented people to get his creation off the ground. Still, it's impressive as hell. There are hidden zippers all around the suit, sneaky shoe uppers tied to the feet and incredibly detailed color representation. It's pretty much perfect.
The whole process is fascinating if you're into the DIY process (or appreciate thoughtfully detailed cosplay). MoonSpider first got the Spider-Man suit pattern in a digital painting file for printing on 4-way stretch lycra fabric at a dye sublimation printer. He describes the printing process, as basically "a giant printer that uses heat transfer to move fabric dyes from a printed color panel directly into the surface of the fabric by sublimating the ink from solid to gas."
The eyes are fantastic too. He got the frames made from black onyx and the lenses from flexible mirrored plastic with a white vinyl overlay. Perhaps the most important detail was to get the perfect seamstress since sewing in zippers to make the whole suit look like one piece is pretty difficult.
If you want to read more about the whole Spider-Man suit process (and you really should), head over here. It cost MoonSpider around $600, with a lot of the resources found from The Replica Prop Forum.