Raistlin Majere, he's a pretty complicated character whose role evolves a lot during the series, but if you allow me to count him as a villain then he's definately the most memorable one for me. I loved reading the Dragonlance series and have read a lot of the books more than once.
Another really memorable villain from books is Artemis Entreri (Forgotten Realms).
Another really memorable villain from books is Artemis Entreri (Forgotten Realms).
