I have also heard people recommend Bitfloor recently... I have never used them and I know they have had issues in the past with security.
Since it's been so hard to buy with Coinbase I've been using Bitfloor.
I'm not too worried about their past security problems because I don't let them hold my funds longer than necessary. I deposit cash at BoA, buy bitcoins as soon as the deposit is credited to my account and immediately withdraw those bitcoins to my own wallet.