From my perspective, comments should generally be limited to method level comments (javadoc or .net xml type comments) for the generation of documentation later and TODO comments. Beyond that I think in most cases commenting is superfluous, time-consuming, and slightly annoying. If you really think the person who comes behind you can't figure it out, then refactor it or at least put it in it's own method with a method level comment.

From my perspective, comments should generally be limited to method level comments (Javadoc or .NET XML type comments) for the generation of documentation later and TODO comments. Beyond that, I think in most cases commenting is superfluous, time-consuming, and slightly annoying. If you really think the person who comes behind you can't figure it out, then refactor it or at least put it in its own method with a method level comment.