The one that comes in the box!
For at least the past year, the new G19s, that I have tested, right out of the box, a 5lb trigger that is so smooth, but crisp, seems lighter than the 5lbs they weigh in at, even the two I have bought, clean as glass.
The great advantage of the factory standard, 2k (5lb) in a G19, my favorite glock, if you go to places you can not transport a personally owned pistol, using a borrowed weapon, no problem at all, it feels the same as your left behind Gun.
Shooting many rounds with the factory standard, 5 lbs trigger leaves your brain/finger in a position of no surprises, at home or away from home.
The shots fired are the same, the reset the same, your life might be on the line, or you might be shooting an IDPA match for instance, with a borrowed
Glock 19, you should always use an identical trigger.
Quite possibly the different differences in trigger weights are overrated as a place to attack you in a law suite, the same in your shocking Dumb Dumb rounds (Hollow Points) being deployed against the poor under privileged criminal who tried to stab you! But it is a good idea, using the same trigger always.