Currently, Google. Not necessarily because they are world-leading trendsetters in all things internetty, but because they have acted as the ultimate facilitators in internet-related development over the past decade. Whether you like Google or not, the online world wouldn't be what it is without their contributions (and investments, and acquisitions).
Huge collection of porn.
Seriously though, I would say the fact that in theory, we can have knowledge accessible by anyone on the planet, and that's awesome. I believe on day it will.
The end-to-end architecture of the IP layer, enabling the level playing field for new apps and protocols, and letting anyone be a content provider or p2p node.