It would probably be the one you didn't list, the 3904/3906. If you really want a nice 39 series get the 3913/3914 (compact version). All that being said, I like all of the triggers on my mod 39 and 39-2. Also, this is a matter of taste and how well the gun was made. All of them were made to be reliable but there are some triggers better then others, even on the same model.