Blueeyedtiger (From Furbid)
Very easy to work with, pays promptly and quick to reply to communication. Good character descriptions, but still allows artist flexibility :)
Shetani (From Furbid)
I have done a couple commissions for him, and he is very pleasent to work with as well. Has great ideas and is thorough in his descriptions.
I know someone had a complaint about him earlier, but I had done a couple commissions for him last year and had always had prompt payment and good feedback. If he was busy, it may have a taken a bit longer to get replies, but he did usually reply within a week at most.