Here's one from left field:

I can understand, being that GoldWave can run DirectX plug-ins but not VST, why this may not be the most popular audio editor on the market. However, this app has been available for 'round about 13 years and the benefits of time and experience have finally shown through.

I'm of course referring to the Expression Evaluator.

This is an amazingly powerful tool which I have not found available on any other audio editor I've encountered. This tool allows you to create sounds or DSP effects using simple (or complex, if you'd like) mathematical expressions. Those already somewhat familiar with DSP programming should find it cake to use - although newcomers should find it easy to grasp as well. In the two weeks since I've owned it, I've already created a slew of modulating pitch, granular and filter effects using just the Expression Evaluator.

Add to that your standard array of compression, filter, delay, reverb etc. effects as well as analysis tools and you have a well-rounded and extremely flexible editor. Oh, and it's dirt-f***ing cheap at 45$(US).

So far, I've experienced no stability issues on my HP dv6000 laptop.