I manage to separate the art from the artist, in other words I'm more than happy to watch Spacey's movies such as the excellent L.A. Confidential, K-Pax, Seven, etc. He was a great actor and there were a lot of other people involved in the making of those movies besides Spacey, should people stop watching them just because of him?

You also have to ask yourself where you draw the line. How many movies should we avoid watching because one person involved in the production has done something illegal?

Look at Die Hard - director John McTiernan has served prison time for lying to an FBI investigator and perjury (https://en.wikipedia.org/wiki/John_McTiernan#Criminal_charges,_felony_conviction,_and_incarceration), in which case should we all stop watching Die Hard and his other movies? Of course not.