He wrote the first side-scrolling engine for PCs (long before they were called that) back when it was considered impossible.
He made people sit up and take notice of Shareware
He wrote the engines for Commander Keen (2d platformer) Wolfenstein (3d) , Doom (3d with variable height floors/walls), Quake (full 3d), Quake II (coloured lighting etc) etc etc
He's one of a very small number of people who were writing groundbreaking code right at the beginning, and are still writing groundbreaking stuff.
He's constantly made his code public, as much as possible
He loves fast cars; how does a 1000hp twin turbo w/24psi of boost Testarossa sound? (that was 11 years ago)
He founded a company that builds and flys some serious rockets. real ones.
Seriously, if that doesn't make you a coding god, what does?