Wow, you have to pick between Microsoft and Apple???
Oh well, I would choose whichever one corresponds with the most hardware you own. If you have an iPhone and an iPod but still use a PC then QT, if most of your hardware is MS and you don't want to look into other options, like DivX and Xvid, then use AVI.
Tony
"...an eye for an eye leaves everybody blind" - M.L. King