Place chicken breasts in the slow cooker, cover with 1/2 to all of the buffalo sauce, depending on how spicy you like your sandwiches. I do 1/2 the bottle.
Cover. Cook on low for 4-6 hours or on high for 2-3 hours. When done, it should easily shred with a fork.
If desired, butter buns and place on a cookie sheet, open faced. Bake on 400 for about 5 minutes.
Place shredded chicken on the buns. Drizzle with ranch or blue cheese dressing, if desired. Enjoy!