Who is your favorite bad guy in the Lord of the Rings?

[greyhavener]

I thought Saruman was the most interesting bad guy. Gandalf turned to him for wisdom and support, but Saruman's desire for power had already corrupted him by the time Gandalf arrived in FOTR to consult with him. I want to find the story of how this transformation took place. Did Sauron deceive Saruman or did Saruman have a character flaw that only surfaced when the opportunity to rival Sauron presented itself? I find it very interesting that even after Sauron's destruction, Saruman went about doing small evil, unwilling to admit defeat or submit to another's leadership. This is a fascinating end for one who was once, at least in other's perceptions, Gandalf's better.