I have a microwave crisp maker which I use from time to time. Thinly sliced potato (skin on), nuked for however long it takes, no salt. They aren't bad and go well with a dip. I reckon that is pretty healthy!
Unfortunately, it only works with bog standard potatoes, not sweet potatoes or apples or whatever. I have a dehydrator which will deal with those, although it costs a lot to run so I don't do it very often at the moment!