Ask HN: Best Job Posting Site for Hiring

What is the best job posting site (e.g. CareerBuilder, Monster, Craigslist, etc.) for hiring a new developer? I'm thinking in terms of response rate and quality of applicants.

I know I read an article where some software company blogged on the subject with their results and metrics, but I cannot find that post to save my life. I thought it was either 37Signals or FogCreek.

Anyone have any insight?