When setting up a new computer heres the goods to install for video work.
Handbrake
Has that cocktail logo - Good for getting things off DVDs and transcoding.
http://handbrake.frVLC
Plays videos that quicktime balks at, transcodes, play weird internet videos, is pretty magic to have. VLC is needed to make Handbrake work.
MPEG Streamclip
Kickass for fixing and transcoding wacky video formats that just aren't working.
Tricks
(open package contents right click)