From my surveys of a few hundred hardcore Bond fans, asking for a top five, the top ten vote-getters are:
1. Casino Royale (2006)
2. From Russia With Love
3. On Her Majesty’s Secret Service
4. The Living Daylights
5. Goldfinger
6. For Your Eyes Only
7. Thunderball
8. Licence to Kill/Dr. No (tie)
10. The Spy Who Loved Me

From the IMDb’s survey of over 11,000 users, asking only for one favorite Bond film back in December of 2006, the top ten vote-getters were:

1. Casino Royale (2006)
2. Goldfinger
3. GoldenEye
4. From Russia With Love
5. Dr. No
6. On Her Majesty’s Secret Service
7. The Spy Who Loved Me
8. Live and Let Die
9. You Only Live Twice
10. Thunderball