Based on the game by Tinker Bell.

What pencil is best for drawing anime?

Ignore the person who just replied, they are a ignorant person who probably wants to commit suicide themselves. Really, there is no certain pencil you have to have, I find any works. However, many like to use mechanical pencils(The Best Mechanical Pencils) -some even use special ones, I guess its because it has a small lead, and does not require sharpening.
It all comes down to what you prefer. There are also prismacolors col-erase pencils that anime artists like to use for rough sketching since it writes very softly-in either red or blue- and is not as easily seen- so they can add graphite pencil to later to make a cleaner sketch, and it is so light it is barely noticeable and is erasable.
It is not necessary though. If you are into shading your anime illustrations, not coloring, I recommend staedtler lumograph graphite pencils, they are great and come with a great variety of hard and soft pencils that create perfect shading, and the pencils are not cheaply made-and for a good price. Now if you mean for inking- I recommend either copic multiliners or micron pens(made by Sakura) and if you use watercolor a pentel brush pen.