Having practiced yoga for quite some time now, my collection of poses to choose from is pretty vast. While my type-A-ness loves the challenge and push of Crow (and its many variations), my MOST favorite pose is Viparita Karani. Good ol' Rodney Yee was the first to introduce me to it and it really was love at first pose. In Legs Up the Wall, I feel most myself, sort of like I'm coming back into who I am. It is THE most refreshing pose for me and sometimes I like to end my practice here, instead of in the traditional Savasana.
I've also fallen asleep in this pose, which speaks volumes considering I'm an insomniac! :) However I don't recommend letting yourself fall asleep here unless you enjoy the ouchy pins and needles effect. Yikes!
Benefits: calms the mind, eases backaches and tired or swollen legs and feet, cleanses and restores the body and mind.
If you've never tried it, you absolutely must. I guarantee it will become a part of your practice. I always work it in, sometimes just by itself anytime during the day, and there really is no better restorative pose.