i use iTunes for my music (or iPod ), and for videos I use windows media player for the movies, or quicktime player if I have converted the movies for my ipod but not watching on ipod. I used to only use wmp for music and movies until i bought my ipod.
I used iTunes for the longest time. I was reluctant to switch, not due to iTunes being the best, but because I was so familiar with it. How when I downloaded Songbird, and the downloaded the iTunes skin, I was in heaven.
Now I have the functionality of Songbird, but with the familiar feel of iTunes.