I've had some lovely commissions done this year. Like the one in my icon. That's by IceLyon, so I'd like to start this off by saying he was great to work with and I highly recommend.
One person I don't recommend is WolfgangCake
I commissioned a basic sketch from him back in June, no more than two hours worth of work, not even inked. I talked with him for a while and agreed on payment - he would do a rough outline, I'd pay half the payment, then he'd finish to detail and I'd give him the other half payment.
About a day later I got a -very- rough outlined. Fair enough, I said, and paid half. I then waited for the final version, ready to pay the other half. I'm still waiting.
For the next few months I received nothing but promises and assurances. First he told me that he'd be scanning it over the weekend, then he told me that he was moving house (seems that's a line that crops up a lot) and wouldn't have internet connection for a month. Strangely, during that month he had no problem leaving comments on FA. Then after that month he 'lost' the image, insisted on wanting to redraw it, promising that he had the original saved somewhere, and the last contact I got from him was September 18th. I've given up trying to get a pic from this deal.
So in essence, avoid.