Off all the accelerators one shines far above the rest. The MIT, Harvard and Stanford of the accelerators is clearly Y Combinator. What is often overlooked is the network that accelerators provide, it's something you can't see in any of the accelerator databases figures including my own.

FastCompany has produced a facinating infographic look at networking at YC.

Source - http://infographics.fastcompany.com/magazine/163/y-connector-xl.html