Barbara Bach was nice. So was Halle Berry.
My favorite though is Jill St. John in Diamonds are Forever.
Ursula Andress (Dr. No)
Maud Adams (Octopussy,The Man With The Golden Gun)
...and if you count the spoof Casino Royale, Dahlia Lavi:
Honorary Mention: Maryam D'Abo (The Living Daylights)
Overall, I'd pick Jill St. John (IQ 162) or Maud Adams (seemingly the most character).
Cheers!