Suppose I enjoy eating plain potato skins. What bracha would I make?
As always, please cite your sources.
If your potato skins being plain means that they are not cooked, then they are shehakol - Berachos 38b - anything which is normally eaten cooked, if eaten raw is shehakol. Potatoes are normally eaten cooked.
If they are cooked, then they would be ha'adama, as potato skins are normal to eat along with the potatoes (as opposed to many fruit peels which are removed before eating).
Additionally, Magen Avraham 202:17 considers any peel that is "part of the fruit" i.e. doesn't fall off as it develops to have the same blessing as the fruit - מגוף הפרי הוא, and would have you make a ha'etz even on an orange peel. The potato peel is no less part of the potato, and would therefore be a ha'adama regardless of whether or not it is normally eaten.
As always, CYLOR.
The laws of brochos are very difficult. CYLOR.
But I found at OU guide to blessings and “The Halachos of Brochos” by Rabbi Y P Bodner that “the blessing on candied fruit peels that are not usually eaten is 'shehakol'”. OU quotes the Chazon Ish, Orach Chaim 33b.
I assume the law is the same for potatoes. Now all you have to do is determine whether potato skins are normally eaten. From the wording of the question “Suppose I enjoy eating plain potato skins” it seems that plain potato skins are not eaten and I deduce the blessing is 'shehakol'.