Neat Video from neatvideo.com is truly outstanding. (Though they could seriously do with updating their website examples, which don’t give a real idea of its power.)
It’s a plug-in for After Effects (which I haven’t tried) and the open-source VirtualDub (which I have), amongst others. The downside is that it’s currently only available for Windows (Mac version in the works apparently).
That said, if you have Intel machines, it works fine in Parallels, etc. We had to do some e x t r e m e noise reduction on HVX200 footage shot at night with way too much gain. I really thought it might be unsalvageable. The mixed-platform workflow was tricky (with VirtualDub/Windows/Mac codec issues: we ended up creating IFF image sequences of the shots) but the results were absolutely amazing.
Spend some time learning the advanced interface, and you’ll get results you wouldn’t believe possible.
Ben