Among my favorites are Jerusalem artichokes they produce a fairly high yield of starchy roots that can be used as a substitute for potatoes. They grow wild across most of the country. If you plant them in your yard, most people simply assume they're some sort of ornamental.
I like wild rice but that's simply not worth the trouble. I planted some New Zealand spinach last year and I've discovered that it returns in force the next year all over my garden.
I have a lot of these bordering my driveway.
You know, they were introduced in the 70s as cheap cattle feed and the cows won’t eat them. I have never met a human who professed to have enjoyed them, either.