Marc Andreessen and Ben Horowitz

This year is shaping up to be the biggest for VCs deals in a decade--with a flurry of from activity well-known startup backers and a new breed of investor. What follows is a list, entirely subjective, of those with outsized influence.

Marc Andreessen and Ben Horowitz
This duo has been going at it since they teamed up in the mid-1990s at Netscape Communications--the company that ushered in the first Internet boom, fought a monstrous antitrust battle with Microsoft, and turned Andreessen into a celebrity. That led to Loudcloud, which led to Opsware, which they sold to Hewlett Packard in 2007 for $1.6 billion.

Next came Andreessen Horowitz, the VC firm, in mid-2009, and these guys are raising money and funding companies like mad ($1.2 billion now under management). Some investors complain that they’re investing at overly high valuations, but it's certainly not slowing them down. Added to their portfolio in 2011: Fab and Pinterest, two of the fastest growing consumer properties; cloud powerhouse Box.net; and Airbnb. Other stakes include Groupon, Foursquare and newly public Zynga.

My favorite Andreessen-Horowitz play of 2011 involves a little Internet payback. Andreessen and team sold Skype--which they'd bought control of with a group of investors in 2009--to Microsoft for $8.5 billion. Andreessen and his team more than tripled a $50 million investment in 18 months.