Potatoes have are a great source of many minerals and a healthy option for a carbohydrate. They may raise your blood sugar rather quickly, but so will your typical pasta. If you eat the skin, that is a decent source of fiber, so that should slow the absorption of the carbs. Potatoes are actually significantly higher in potassium than bananas, go figure.
However, it is hard to say whether or not potatoes or pasta are going to be a benefit to your diet depending on the rest of your food intake. Assuming you are not overindulgent in calories or carbs, then I would suggest potatoes. But, variation is always a great idea, so maybe you can switch to pasta occasionally.