Face it: you'll never be Master Chief from Halo. For one, he's a fictional character. But beyond that, you just don't have the constitution to be a Space Marine. But hey, you can still dress like one.
Ecko just released a limited edition ODST hoodie to coincide with the launch of Halo: OSDT. When fully zipped up, it'll make you look as threatening to hostile aliens as you're ever going to look. You can buy it now for $88.