Nexus 5

Co-worker received his two days ago and it's not a bad phone. I'm on the fence still. I love softkey approach other than power and volume as the physical buttons. But the phone felt a tad light that it might fall off with a breeze (I might be in the minority here). 

Nexus 5 Review: Flagship hardware for half the price
$350 gets you a Snapdragon 800, 2GB of RAM, and a fast track to future updates.