iTunes (Free)
Songbird - Sure iTunes is a free, capable media organizer. However, it doesn't work well with non-Apple products. Instead, use Songbird. It supports more file types, can import iTunes libraries and handles more types of media players.

Sibelius ($600)
MuseScore - Need to whip out some music notation for your band? Maybe you need simple exercise worksheets for a music class. This free music notation program has you covered.

Norton Internet Security 2012 ($70)
Security software - You don't have to spend a bundle to get good computer security. Visit my Security Center for lots of excellent, free alternatives.