Place eggs in a heavy-bottomed pot and cover with cool water by 1 to 2 inches. Vent lid and bring just to a boil. Cover pot completely, lower heat, and simmer for 30 seconds. Remove from heat and let stand, covered, 12 minutes. Transfer eggs to a bowl of ice water and let stand for 10 minutes before peeling under cool running water. Slice eggs in half lengthwise and fill according to your chos
In a large bowl, use a fork or small whisk to mash together 6 full egg yolks, mayonnaise, sour cream, and Dijon mustard until smooth. For a very smooth and creamy filling, you can use a use a hand mixer (my preferred method) or a food processor. Season to taste with salt and pepper.
Using a spoon, a pastry bag fitted with a star or plain tip, or a zip-top plastic bag with one bottom corner snipped off, fill each egg with some of the yolk mixture. If desired, sprinkle each Deviled Egg with a pinch of paprika or chopped fresh herbs.
Following "classic" method above, combine 6 full egg yolks, mayonnaise, sour cream, Dijon mustard, cream-style horseradish, bacon, and chives. Season to taste with salt and pepper, adding additional horseradish if you prefer a spicier filling. Fill each egg with some of the yolk mixture and, if desired, garnish with additional bacon and chives.
Following "classic" method above, combine 6 full egg yolks, mayonnaise, 1 teaspoon extra-virgin olive oil, garlic, basil, and lemon juice. Season to taste with salt and pepper.
In a small skillet over medium heat, warm remaining 1/2 teaspoon olive oil. Add bread crumbs and stir to combine, until crumbs are lightly toasted. Transfer to a bowl and season with a pinch of salt and a few grinds of black pepper. Let cool. Stir in Parmigiano Reggiano and lemon zest.
Fill egg halves with garlic-basil yolk mixture. Sprinkle each egg with breadcrumbs just before serving.