I just stumbled upon Ruby Monk two days ago and loved it. I've done some Ruby in the past and needed a refresher. CodeSchool seemed very disjointed, even for someone who isn't a beginner. Ruby Monk takes you through the basics without dragging it out and logically progresses so that you're never at a point and wondering how you got there or what it has to do with what you learned before.
Ruby Monk has the perfect formula for self-paced language learning.