Wanted: Really good audio software

I have downloaded some music from the internet (paid for of course), and want to create cds. I have found that most programs that I have cannot read or write to even popular formats like mp3. I have Audacity and that is terrible. It won't read some formats and it has its own format that no other program can use.
I need a really good free, or cheap, program that will let me convert and open other formats like mp3, wav, aiff, and others. I cannot buy a program just to discover it is very limited. So I'm asking you guys to help me get the best one for the money. I'll even pay ... yes pay for a program that won't let me down. Thanks.