Check your discs!
It's so easy to buy something, and leave it in the cellophane for when you next have time. You can have unwatched discs stretching back years!
I bought the 20th Century Boys trilogy, telling myself I'll get around to watching it when I have time. And yesterday, got to movie three, and it died after the layer change. Freezing, chugging, pixellating and dying on all my players.
Now 4 Digital Asia, who released the boxset don't exist anymore, although4 Digital Media still does. I doubt they'll be offering any replacement discs, and neither will the store I bought it from... Play.com way back in 2010.