bellard.org - has the most impressive portfolio of software created from a single developer I've ever seen. It's more astonishing how varied each of his accomplishments are - covering some of the hardest programs in different computer science fields.
He's by far the best programmer in my book, I'm not sure who I'd put at #2, there's a number of contenders, but anyone else I can think of are experts in their respective fields, I don't know of anyone who has compiled such a broad list of complex software covering that many different fields.
But that's mostly by choice as he's predominantly a professor who spends most of his time teaching so he's obviously going to have created a lot less body of digital works than a full-time developer is going to have.