I use "Quick Media Converter" it's posted on c-net, GPU-GNU, so it really is free, like firefox, etc. It converts practically any format to and from any other, but I like to convert avi and mpg to wmv, I don't see any loss of quality, and QMC can even change fix the aspect ratio when it's distorted. I've tried several media players, unfortunately WMP seems to me to be the best, but that could change any time.
I also use firefox and the DownloadHelper add-on, which is great not only to dl videos (seems to be the only way, on xvideos, spankwire, xnxx and tube-type sites), but DLHelper is also fantastic for pics because you can download all the pics on a page with one click (99% of the time), without opening the thumbs, and it even makes a separate folder for each page so you don't have to screw around renaming every pic. You can even leave the page and surf on, and get way ahead of your download que. I spent the evening going through a four page thread, ripped 50 pages, (just the jpegs, none of the bullshit) that's almost a thousand pics in a couple hours. I'm in hog heaven, Peachy is gonna keep me busy for a long time!