Coinbase - Bitcoin, safe and easy.
Bitcoin Wallet - Bitcoin Wallet is a mobile application that allows you to send and receive digital currencies.
Bitfinex - Bitfinex is the largest and most advanced crypto-currencies trading platform.
BitStamp - Provide reliable and easy to use service for companies and individuals to exchange bitcoins.
LibertyX - Buy bitcoin anonymously at thousands of locations in the US
Mycelium Bitcoin Wallet - With the Mycelium Bitcoin Wallet you can send and receive Bitcoins using your mobile phone.