I went with the Shimano Ultegra SPD's after much research and discussion with my LBS folks. I am very happy with my choice, I have a lot of confidence in them, and they are VERY easy to clip out of, which was important to me.
However, I am not writing to give you a specific recommendation, rather, I would like to suggest that you do something that benefited me greatly as I made the transition to clipless:
Mount your pedals and cleats, and then mount your bike to a trainer. I spent 3 consecutive nights on the trainer, about 1/2 hour a night, practicing cleating and uncleating, and making slight fore/aft cleat-to-shoe adjustments. The second night, I "got it", and my confidence increased exponentially. After the 3rd night, I felt really eager to get out on the street.
So far so good, no wipe-outs yet. I always think ahead about unclipping before stopping, but practicing on the trainer for those 3 sessions helped me immeasurably, and I strongly recommend the practice to anyone who looks to make an easy and safe transition to clipless pedals.