Until this thread I never even thought of making jacket mashed potato. Now I know I will never make them any other way - I hate peeling.
mmmmm mashed taters, I can feel a pregnancy craving coming on
Peeled. I had never heard of leaving the jackets on either. Doesn’t sound yummy.
Both.
Cooking tip - if the kids prefer peeled. Cook them all unpeeled, quarter the smaller ones and peel before mashing for the kids. Usually the skin just peels off in one piece. Mash the rest skins and all for the big people. Butter++++, warmed milk/sour cream for beating through for a silky texture.
Peeled, mashed with cream, served with butter
I’ve always been a peeled girl… I didn’t even know mashed potato came in unpeeled versions! LMAO
As for recipe… I’m really boring. Potatoes, peeled and mashed. Add salt and margarine. If I’m feeling really enterprising, I’ll add some parmesan cheese (the pre-grated stuff) and pepper.
God, I’ve just realised how boring I am!!
Max 
I can never be bothered to peel potatoes. I just wash them off, cut them into chunks of appropriate size and boil 'em. Sometimes I don’t even bother to mash them, just pile the chunks on the plate and add butter & salt. Cream-style corn is good with 'taters too.
I tell ya, mashed patatas are of the devil 
d&r*********
Depends on my mood.
I’m suprised only two other folks here use a ricer. Of course if you leave the peel on it clogs the damn thing.
Yukon gold if I can get them or red
Peeled, boiled, riced and mixed with fresh crushed garlic, a little butter and ranch dressing.
With the skin if I have a choice. Instant only if I have no way out.
Unpeeled, lumpy, tonnes of garlic. Any other method of preparation is folly.
With jackets, boiled with lots of galic cloves which are drained and mashed in with the spuds, butter, sour cream and some bacon if I have it. Mmmmmmmmm.
Peeled
Red potatoes, leave the skins on. Add sour cream, chives & cream cheese.
I’m shocked, I tell ya.
Only about 60% of the answers here are for peeled. I was under the (perhaps mistaken) impression that only the swankiest of swanky left the skins on.
We’re a peeled family at home but we don’t have any objection to skins when dining out.