These days I use an Audio Technica AT-3035 microphone. It's plugged into an Audio Kontrol 1 audio interface which plugs into the macintosh. For audio recording software I use Garageband with no added plugins or anything. I hit 'record' on garageband and I record the video on a little Sony Handycam. Once I've got a take i like, I import the video clip from the camera into Imovie. I remove the audio that was captured by the built-in camera mic and overlay the newly mixed mp3 stereo version i recorded with the mic in garageband and synch it up with the video. It took a while to learn how to do it all and i pulled out several hairs in the process, but it's actually pretty easy all said and done.
On some older clips i combined the AT mic with a Shure SM-57.
Then the oldest clips were recorded using a couple of different cheap video conferencing mics/cameras directly to the PC that i was using at the time.