CampBX seems simple enough.
Once verified I can transfer funds to them straight from my bank.
is it ach?
You can use ACH with CampBX, but there's a $2 fee. Dwolla is free, however. ACH stands for automated clearing house - it's the system that's used to transfer money between bank accounts in the United States, equivalent to SEPA in Europe.
As far as the question itself, the answer depends on where you live. I would agree with bitstamp if you live in Europe. I've used Coinbase and it's even easier - I find it really simple and straightforward to use. So if you're in the United States, it gets my vote hands down for easiest way to buy bitcoins. I'm probably going to switch to CampBX because it's easy enough, and the fees are half what Coinbase charges, so it'll save me money. But for ease of use, I think Coinbase wins over CampBX.