TuneUp

Quite possibly the most important piece of software any music lover can buy, TuneUp ($30) can take any messy iTunes database and turn it into the pristine sort of collection reserved only for those with indentured man-servants (as demonstrated here). TuneUp's killer tuning capabilities comb your music collection for anomalies, replacing erroneous metadata, adding album covers and quite a bit more (it'll even tell you when your favorite musicians are touring). And since you all are such a special bunch, from now until the end of March, TuneUp will give you 15% off if you use the code UNCRATE when checking out.