swf, flv, wma, wmv

i have dl'ed multiple shareware and freeware apps from the apple site that were supposed to play and convert multiple media types, most importantly swf, flv, wma, wmv;
each app that i dl'ed either gave codec overrun error or was damaged in extracting with stuffit;
i have vlc player installed, is there some sort of conflict going on?
other files zip and unzip fine with stuffit, other programs can be installed fine;
i have just had no luck with either getting the files to play in quicktime(free version) or an easy to use converter to .mov or .avi or .mp4
anyone have a good program that is free?

Perian
Perian - The swiss-army knife of QuickTime components

Download this then most of those file formats will work in quicktime. Should work for VLC too.
And for the wmv, you can use flip4mac.
And lastly, if the music/video you want to play is a drm encrypted wmv/wma file then it can not ever (as far as I know) be played on a Mac. Only drm free wmv/wma can be played on a Mac.