As an ObGyn working in Boston I like the Harvard courses held in the Four Seasons in Boston called "Annual Update in ObGyn". Presented in spring and fall by the most excellent faculty of Brigham and Women's Hospital and the MGH. I attend every one to two years. You might check for alternatives at Yale, Duke, Cornell, UC San Francisco, etc. These courses allow you to get in touch on a personal basis with the very approachable faculty and you also get excellent materials with the course.
My daily dose of CME comes from Audio-Digest CDs, "the spoken medical journal". I get a CD in the mail every two weeks (it also comes as MP3 or cassette if you are one of those people who drive a Volvo 240 wagon and live in Cambridge). It is the best CME program I have found. The recorded lectures are given by good, renowned, expert speakers, many of them nationally known, on topics that really matter. I listen to the lectures in my car on the way to work and back, over and over again until I am bored. It is a very effortless way of learning, the material kind of diffuses in.
And, yes, I have tried the ACOG audio program. I did not like it, too superficial, not as relevant as Audio Digest for daily practice.
I have also tried and stopped a subscription to the cassettes by Oakstone Publishing in Alabama. They advertise that they scan the literature and select the most important articles, summarize them and comment them. Well, not quite. The selection is by far not as good as the ABOG selection and the comments are mostly simple repetitions of the summaries.
The other best CME is the ABOG list of publications and the corresponding questionnaires. Can't beat it - you keep your board certification up to date plus you get a select list of relevant publications plus you get CME credits.
My favorite other source besides the Green Journal of course, is the throw-away journal "OBG management". The chief editor is Robert Barbieri, the close-to-genius director of ObGyn of Brigham and Women's Hospital, who has an uncanny sense for what is truly important and relevant at any given time.
The best medical database that I consult frequently is "uptodate", written almost exclusively by Harvard faculty. It is very, very readable, precise, evidence based and last not least, up to its name it is up to date. About 500 a year. Uptodate also has some of the best medical information for patients on their website! Direct your patients there to avoid them falling prey to weird internet rumors.