What thickness is the best for a guitar pick?

There is no definitive answer to this, as it depends on the player's preference and the style of music being played. However, here is some general information about guitar pick thicknesses:

* Thin picks (less than 0.50 mm) are typically used for acoustic guitars and for strumming chords. They provide a bright, crisp sound and are easy to play.

* Medium picks (0.50 to 0.75 mm) are the most versatile pick thickness and can be used for both acoustic and electric guitar. They provide a good balance of brightness and warmth.

* Heavy picks (more than 0.75 mm) are typically used for electric guitar and for playing lead guitar. They provide a thick, warm sound and are good for shredding.

Ultimately, the best way to choose the right guitar pick thickness is to experiment with different picks and see what works best for you.