In a row, probably never but I love the capability of being able to watch what I'm in the mood for at a whim. Not being interested in a action movie, I can watch something drama. Or if I want to watch explosions or what not, I can. Or if I want to watch some of my HBO:Rome, I can do that, too. Or a Star Trek episode/movie or a Star Wars flick, etc.
I usually keep 15 or so in iTunes on my laptop at any one time and usually thence to my iPod classic. Never know if I'm going to be in the mood for something or the other.