Place the chicken breasts in the slow cooker in a single layer or stacked but evenly distributed for even cooking.
In a small bowl, whisk together the hot sauce, melted butter, ranch or blue cheese dressing, garlic powder, onion powder, salt, and pepper until smooth.
Pour the buffalo sauce mixture over the chicken, making sure every piece gets a good coating. If needed, turn the chicken once to coat both sides.
Cover and cook on low for 6–7 hours or on high for 3–4 hours, until the chicken shreds easily with a fork.
Carefully remove the chicken from the slow cooker and shred it with two forks. Return the shredded chicken to the pot and stir to coat in the sauce.
If you’d like a thicker sauce, simmer the mixture uncovered on high for 10–15 minutes, or blend a small amount of cornstarch with water and whisk into the sauce, cooking until it thickens to your preference.
Taste and adjust seasoning, adding more salt or hot sauce if you crave more heat. Serve as is, or with celery sticks and blue cheese crumbles on top. It also works great as a sandwich or lettuce wrap filling.