Spyke

Generally in the middle, higher if it's a 2D game using subtle 3D for the UI.
I've also had cases where I had in barely on just so i could get the extra resolution. Some homebrew looks nicer like this.

4

New N3DS - somewhere between half and max setting for 3D games and barely turned on for 2D ones. 3D really needs depth to pop while 2D starts to look too much like a paper cutout with setting too high.

3

You reached the end

[3DS] Where do you guys like your 3D slider at? | Spyke