oh yes the Princess Bride, but if I pop that in I cannot do anything until it's over for functionality I'll pop in any of the Firefly Eps.
For anime it may come as a shock to those who know my gallery but yep, its Fruits Basket!
Several live-action favourites include Lord of the Rings (I'm currently rewatching each one with each of the four commentaries), Mary Poppins, Blazing Saddles and A Better Tomorrow (early John Woo classic).
In terms of anime, the titles that lift my spirits are My Neighbour Totoro, Jojo's Bizarre Adventure and Fist of the North Star. Of course, anything Hentai goes without question *heh*
Like ReiTheJelly, I've got a couple of thousand discs so there's no shortage of choice. Still, there's never enough 'spare' time to watch much, even if the telly's on the blink.