While Audacity sure ain't great, I've used it for several years with great success and few complaints. As you know, it hasn't cost me a dime. If you have basic, straightforward editing to do (cut tracks, create fades, minor amplification or normalization) or small amounts of more complicated editing (high pass filtering, volume envelopes), it's a fine and dandy program, IMO. I'll spend money when I need something more complex, but since I typically record in ideal, simple situations (on stage, two track stereo mixes, primarily), I've really got no need at this time.
I also think it's a great way to learn without spending any dough. Once you've maxed out its limitations, you'll know what you need and want to spend your money on.