People who know me, know I like open source software--and for audio, I love Audacity [Corrected Link]. (Check out some of the old posts for a review...) Audacity can tackle almost any recording project you can think of, but it doesn't really "make" music.
When I saw that Sony had $30 off thier ACID and VEGAS lines of software via a rebate, I jumped on the already value priced ACID XMC.
I was a big fan of ACID when it was owned by Sonic Foundry and the newer version hadn't really added much functionality. But at a net price of $5, it's hard to go wrong.