Favorite non-Blofeld villain that's a member of SPECTRE?
Quantum villains are included.
Kronsteen is probably my favorite. At first you see this man playing chess, no idea who he is or why we're watching this chess match. Then he receives a communiqué, and reports to Blofeld. You immediately see this man is smart, is one of SPECTRE's logicians, and is practically untouchable in the way he carries himself around the organization. And the twist in which he dies contributes to what is in my opinion the best Bond film made.
Dr. No is my other favorite. I like smart villains. Smart villains are capable, period.