looking good so far: Twilio, SendGrid (TechStars), Wildfire (fbFund), MakerBot, TaskRabbit (fbFund), Smule/Khush, Viki, Medialets, Zozi, ElaCarte (YC), 9Gag (500), ReadyForZero (YC), several others @ Series A/B/C doing pretty solid.
smaller but growing well: MindSnacks (DreamIt), 955 Dreams (500), PicCollage (500), Kiwi Crate, Visually (500), AppStack, MyGengo, Erply (SeedCamp), GinzaMetrics (YC), Farmeron (SeedCamp), ZenCoder (YC), Fitocracy (500), StyleSeat.
10+ modest early exits to Google, Twitter, LinkedIn (x3), Amazon, Groupon, Cisco, Facebook, ReturnPath, DemandForce, etc.
(apologies to any juggernauts or others i left out!)
DMC
Honestly, 10 have already exited, and they have at least half a dozen impressive companies in the pipe.
Are these companies AirBnB or Dropbox? Probably not, though Twilio is legit.