Other than Vecna, Strahd is also a favorite villain of mine.
I also love him.
1. He has appeared as the greatest enemy in many adventures, since 1983 I6: Ravenloft
2. He was so successful in his role that an entire setting was created around him
3. There would be no Barovia without Strahd
4. He is a master of necromancy so powerful that he has created a new kind of zombie
5. He's got a full tribe at his disposal as spies
6. Contrary to all vampires, in Barovia he can enter in any house even if uninvited, because Barovia is his home
7. He's featured in many novels and in a Playstation game
8. He's a romantic figure, involved in an unlucky and tragic love
9. He's funny guy. He likes to invite at home every new guest just arrived in Barovia
10. Even if he's ancient, powerful and brilliant he still can improve in tactics. Some items that can defeat him are in his own castle and he has never realized it.