Preheat oven to 350 degrees.
Fry the bacon in a pan until crispy. Drain on paper towels. Discard all but about 2 tablespoons of the bacon grease. Saute the diced onion in the reserved bacon grease until translucent – season with salt & pepper.
Beat the cream cheese, sour cream, mayonnaise, 16oz of cheddar cheese, & the sauteed onion in a large bowl until smooth. Chop the bacon, & fold it in. Spread the mixture out into a 2 quart baking dish. Sprinkle with remaining cheese, & paprika to taste.
Bake, uncovered, for 20-25 minutes.
Serve with crackers, chips, or bread.