Kind of an odd title I guess, I couldn't think of something more fitting, although I'm sure there is a better choice. Anyways, whilst looking around, I came across Nasa's World Wind program and just kind of thought to myself "That's the kind of thing that makes the internet, what makes it what it should be". So I thought, it's not the only thing I can think of, there are quite a few crowning achievements of the internet (and more debatably, human civilisation).  So here they are.

Wikipedia - Truly an amazing project, More so amazing to think it's all donation funding. In a sense, being funded by any single government doesn't seem quite right for its purpose. Wikipedia is essentially, a globally available shared point of knowledge. Incredibly detailed.

Nasa World Wind - Similar to Google Earth, World Wind is miles ahead. It's amazing to have data on hand not just of Earth, but of the Moon, Venus and Mars. And the Sloan Digital Sky Survey. Amazing :)

BitTorrent - A questionable choice given it's regular application in piracy. The BT protocol is however, an amazing idea. Shame it's not more heavily used for legal application, it fits so perfectly with what the internet should be.

SourceForge - The world's largest Open Source software website. Sourceforge has over a million registered users and over a hundred thousand projects 

Everything mentioned above is also...free. The internet truly is great :)