I stopped in at Isley Brewing Company in Richmond, Virginia.  One of their flagship beers is Choosy Mother Peanut Butter Porter.  This is an awesome beer.  The flavor is right-on!  Of course, you pretty-much need to be a peanut butter lover (at least, liker) to enjoy this.  The porter is not as heavy as a stout.  This is very easy to drink.  The peanut butter flavor is very present but not overpowering.  Delicious.  Stop in and try some!