I know some folks who swear by using a ricer on their mashed.
Heres the recipe for "ultimate mashed potatoes" from the cookbook "52 meat loaves" by michael mclaughlin. A highly recommended book.
4.5 lbs russet peeled and chunked
1.25 cups milk
1 tsp salt
1 cup sour cream at room temp
1 teaspoon black pepper
Put taters in cold salted water and bring to a boil, cook 25 minutes. In a small saucepan bring milk and salt to a simmer. Drain taters and force through a food mill or ricer or mash by hand. Do not use a food processor or mixer (I've heard this makes the taters gummy, never done it myself). Put the taters back in the pan you boiled them in and stir for 3 minutes over low heat. Slowly whisk in the hot milk, then beat in the sour cream. Beat by hand or a minute or two until fluffy. Stir in pepper and serve hot with butter.
I also toss in a handful of grated cheddar or monterrey jack cheese. Seems to punch up the flavor and texture a little bit. Oh yeah, and some green onions and bacon goes well on top