Re: What makes a good (bad) villain?
I say it depends on the story and also how the write can pull them off; not just anybody can pull off a purely evil villain without making it seem silly.
I like villains who have a good backstory because, like HiF said, you can connect with them more. You know why they are doing this or why they didn't do that. It adds a lot more substance to a story, and you care more about the "good vs evil" battle. If it was just some random villain who we know nothing about, I'm like, "Uggh, who is this guy?" Of course, though, the villain with the background can be the total SOB.
A bit off topic, but I love those cool, calculating villains. They always give me the chills. :3