Pistol grip vs strait stock on a Marlin lever action rifle---which is best?

The one that feels the most comfortable to you when you sholder the firearm. I've used both, and for general use I prefer the straight grip, but for some reason or another the pistol grip feels better in the prone position. I don't like semi pistol grips in any position, so find what suits you best and buy that,

I have both and like both.

When I'm shooting a straight grip off the bench I keep my fingers (except my trigger finger of course) on the outside of the lever. Anybody else do this?

Best for what?
The grip style has no effect on the mechanical performance of the rifle, it is just the "User Interface".

I have found that I prefer the "pistol grip" stocks, but I don't mind the "straight" stocks on my rifles that have them. I have found that I shoot a little better with the pistol grip stocks, and prefer the feel a bit. That is my preference, and mine alone.

You need to decide what feels best to you.

If we all had the same opinions, the world would be peaceful, but boring...

Its really personal preference, but the pistol grip puts your hand in a more natural and comfortable position.