Audio Hijack Pro
(commercial) With Audio Hijack Pro you can create enhanced postcasts, record streaming radio from applications like RealPlayer, Windows Media Player, iTunes and more, record Skype, iChat, and Gizmo with a single click, and save audio from records (LPs), cassette tapes, and other analog sources into your computer.
(commercial) Boom Recorder is a field audio-recorder, which can be used in combination with high resolution audio hardware, to be used on-stage or film-set. Features include: An easy to use interface, designed for recording on-stage or film-set, records up to 32 channels simultaneously, LTC SMPTE/EBU timecode decoding from any audio input, and supports QuickTime, CAF, and BWF formats.
Final Vinyl makes recording your old records and tapes easy. It has several advanced features including waveform based editing and built-in 10-band EQ.
(commercial) OnAirRecorder is a highly visual digital timer that also directly controls audio and movie recording through start, pause and reset buttons.
Sound Recorder is a simple sound recording application which uses QuickTime.
Sound-Rec-Ed provides simple GUIs to record and edit sound files, similar to operating a tape-deck. Buttons start and stop recording or break incoming audio into separate files. It can cut sections from audio files or join files. It saves files in WAV, OGG, or MP3 format.