As evidence by the thread I started for it, The Living Daylights, easily. It has one of the most realistic and grounded plots of the series, great villians in Koskov and Whitaker, an awesome theme tune by a-ha, some excellent action sequences, a great Bond girl and a fantastic debut performance by Dalton.
 
As for LTK, well I don't hate on it as much as others do, as a matter of fact, I rather like it a lot. But it has flaws, quite a few to be exact.
 
For starters, this is quite possibly the most un-Bond like film ever. In all honesty, the main character didn't even need to be James Bond, and it will still essentially be the same movie. It's a typical 1980s' actioneer that, while fun, isn't Bond.
 
Also, as mentioned: the production values SUCK HARD. Bland direction is present throughout, and the set pieces occasionally look very poor in their design.
 
My biggest complaint is Dalton. He's nowhere near as good as Bond in this one as he was in TLD. He acts out of character quite a bit in the film as well. I always cringe during the scene when Bond kicks M in the stomach and beats up the guards when he gives his resignation. It just felt incredibly out of character. If it was Connery, Moore or Brosnan, they would've done it in a more dignified and 007-esque manner. Dalton giving M and MI6 a cold-shouldered sendoff rather than simply going out of control and beating everyone up would've been far more effective in my opinion.
 
And last but not least, Wayne Newton is in it. With practically no purpose.