Any way to see waveform when using Quick Look on an audio file?
Snapper from Audioease has been the best I've found so far.  I have it set to launch at log in so I don't even have to think about it.  It activates the waveform view you're asking for just by clicking once on any audio file.  It also has many other features like format conversion, export, etc.
It's not free but is entirely worth the cost with the time it saves me.