If a sequel sucks, I definitely don't bother. I don't want to spend money and waste space with shit like Terminator 3, Star Wars prequels, The Godfather: Part III, etc. The only exception, I guess, is the Alien Quadrilogy because I got the box set for only £6.99 (plus postage) from Amazon, which is cheaper than I would pay for the first 2 (and I wanted to see 3, because it was directed by Fincher)...