I've used Audition, WaveLab, and Samplitude fairly extensively. I found Audition the most intuitive (for me), Samplitude by far the best workflow, and I didn't care at all for the WaveLab UI and workflow. I know some people really like Sony Sound Forge, but I don't have any experience with it. Price / performance, I think SAM SE offers the best bang for the buck, but it also has the slowest / steepest learning curve. Not sure which are offering free demos these days, but a poke around their websites should address that easily enough.