Douglas Engelbart. Tim Berners-Lee. Smalltalk is pretty cool, though.
Same for Berners-Lee. Sure, he remains influential over the web's incremental progress on W3C, but anything more visionary seems to be a miss: XHTML, semantic web, the Solid project...
Engelbart invented the mouse and the entire idea of pointing at things on the screen to interact with them. The results of that interaction is now what you call "the web" (hypertext).