Do you want free or are you willing to pay? If you want free, then Audacity is pretty decent. I've never used any others though.
pro tools hands down. There's a reason every professional studio that records digitally uses it. It runs a little different on PC's, but it's still all the same principles
Check my clips out - I used Adobe Audition... it's what they teach the production/radio broadcast classes with at all three local colleges in my area. I can get it to you FOR FREE, if interested - as I believe in the sharing of information. PM me or whatever w/ your IM info.