I have Wave Editor, but never really used it much -- it was just way slow.
For a Mac, I'd really recommend Amadeus Pro. It only was like $40 for a full copy, though it may have gone up since they just released 2.0. Amadeus can do pretty much all you need for editing, plus you can add in VST and Audio Unit plugins to expand it's capabilities, plus it can cut into tracks on sector boundaries, open and save into wav, flac, mp3, AAC, ogg vorbis, etc.
Amadeus does pretty much all you need, but beyond that you'll want xACT which can tag and create MD5's and fingerprints, as well as having other useful utilities. xACT is an absolute must for Macs, and is made by a ts.com member and is based specifically on our needs.