I really like Cool Edit.......it was one of the original studio quality music recording software that was available on the PC.
I started using it in about 1998 and I still use it now.....although it was bought out by Adobe a few years ago and is now known as Adobe Audition.
I've not got the latest version of Audition, but it's still a great piece of kit.
I don't know how it compares to some of the other, maybe more popular, alternatives on the market (PropellerHeads, Cakewalk etc).....but I've always found it to be very powerful but simplistic at the same time.