This link won't be masked.
http://sony-404.vo.llnwd.net/dspcdn/...-trial_enu.exe
This is the Sony Vegas 8 trial. 30 days free before you have to uninstall and reinstall.
It's probably the best thing I've found that's free and the output quality is exceptional, if you configure it correctly (thousands of rendering options). The only problems I have with it are slow rendering speed (5 minutes or video takes roughly 2 hours on a mid-level rig) and laggy preview playback (again on a mid-level rig).
Keep in mind that this is a trial and it doesn't include the legacy plugins kit, which is a pretty heavy loss, but it can and will get the job done.
I think the best part of Sony Vegas 8 is the ability to use old Sony Vegas profiles that you have (If you've used previous versions before).
Note: This is NOT the full version, and Sony Vegas 8 is around 3-4 years old. Expect it to lack support for new audio/video technology that has been released in the past few years.
If you find that you need something a bit more advanced, check the Sony Vegas file repositories for newer trial version. If you're serious about editing, I recommend buying a slightly older version of Sony Vegas when the prices drop (new licenses are rather expensive, but not out of reach on a medium budget).
I think the new package for Vegas includes Sound Forge audio editing, which is basically Audacity with more inter-program support. The whole package costs around $170 or so.
Add: Please do not use Windows Movie Maker. Ever. It's shameful.