I have used BitcoinMint and CoinAbul so far. I would suggest BitcoinMint, it took a week to receive my coins and he communicates very well. CoinAbul 'lost' my orders, failed to respond numerous times to emails and forum messages and took 2 weeks for me to receive goods. They did however try to right this by giving me a 1% coupon, 1%. Anyone want it?
I've also purchased silver from Casascius, but it's quite a bit more expensive. I'm assuming you want to buy it while it's down.
By far my best method of exchange was to talk my local dealer into accepting bitcoin. He did it once for me recently, I think he'll keep doing it now after he made money off me from the recent gain