I started using coinbase but they take about 10% of the market price. If the Mt. Gox price is $110 Coinbase pays $95. They used to trade at the Mt. Gox market price. Any suggestions for a better exchange? I have heard some mention of BitInstant on the forum.
Coinbase doesn't take 10% of the market price, they are the true price of Bitcoin (look at Bitstamp, Bips, Bitpay, and Blockchain also). Mt.Gox's price is 10% higher because you can't withdraw your USD.
BitInstant hasn't been working for a month, and they are facing a class action lawsuit.