What is the best CPM or ad company you have worked with?

Tweet

You all heard of making money with your blog and such. So have you worked with an ad company that worked well for you? Companies like burstmedia and such. What and who have you worked with and why do you like or dislike the company? Have you gotten paid by them or lost your earnings with them? Let us know and we can learn together to see what works and what does not. Thank all in adavance.