I like Javascript, and given the choice I'd use it server-side as well. It's an excellent language; very minimal, lends itself well to concise but powerful code, and can be made to do pretty much anything given a decent API.

Most of the Javascript you look at is terrible because most of it is copypasted from tutorials dating back many years, when Javascript was, at best, not very well understood or known, and not the domain of serious applications. The modern libraries like jQuery and Prototype definitely exemplify how Javascript could be though.