Is there a wrong way to eat peanut butter?!?!?!
The absolute classic American way to eat it is as "PB&J" which is a peanut butter and grape jelly sandwich on white bread. But feel free to use any kind of jelly or jam or preserves. Another classic American twist is the Fluffernutter: a peanut butter and marshmallow spread (known as Fluff) sandwich.
Peanut butter makes an excellent base for savory sauces as well, served over noodles or with chicken. Its often seen in Thai dishes.
Peanut butter is great, as mentioned, on apple slices, celery sticks, carrot sticks, crackers, toast, or chocolate, etc.
Peanut butter pie and peanut butter cookies are also popular desserts/treats.