There are, generally speaking, two schools of thought with regards to bad movie sequels: whereas some people think that a bad movie sequel can ruin a series in its entirety, there are those who think that it's impossible to ruin a truly good movie, no matter how many sequels, spin-offs or prequels you pile atop its legacy. My own opinion falls somewhere in the middle of those two camps. Most of the time, a bad sequel won't deter me from the first movie if it's a classic - I'm not going to let Hollywood's clawing for cash ruin a flick that I hold dearly. On occassion, though, certain sequels do have the power to tarnish those movies which came before them, and once you've been exposed to their poisonous fumes, it's genuinely hard to look back on the movies you loved without thinking about the unnecessary or ill-judged stories awkwardly attached to their waists. Usually this happens when a sequel betrays the original movie in unexpected ways, or by filling in backstory that nobody wanted to see, forcing you to change your opinions because you can't help by feel influenced. Yes, sometimes a bad sequel really can spoil another great movie, purely by association. Here's 8 of that variety, all of which stripped away a decent amount of magic from those movies they spurred from...