Place potatoes in a large pot and add enough cool water to cover by 1-inch. Add a pinch of kosher salt and bring to a boil. Cook for 15-20 minutes, until potatoes are tender and a knife can be inserted into the center of the wedges easily. Drain potatoes into a colander and return them to the hot pot.
Add butter, cream cheese, 1/2 cup milk or half and half, kosher salt, and pepper. Use a hand mixer or a stand mixer fitted with the paddle attachment to gently combine until smooth, adding additional milk as needed to reach your desired consistency. (I often use the full cup; keep in mind that potatoes will thicken upon standing.) Don't over-whip, or potatoes will become gluey.
(Alternatively, I often use a potato ricer to rice the potatoes and then stir in the rest of the ingredients by hand, heating the potatoes on the stove as needed to fully combine the cream cheese.)
Season to taste with additional salt and pepper and serve.
For easy holiday entertaining, make these mashed potatoes a day in advance and refrigerate. To reheat, place the pot with your mashed potatoes inside a larger pot of simmering water (water should extend about halfway up the side of the potato pot). Stir mashed potatoes until evenly reheated. If the potatoes are too thick after heating, add a little extra milk or half and half before serving.