Rhubarb
We have rhubarb in our back yard that originally came from my maternal great-grandmother's house in Chicago. She was a prolific gardener, a tradition that passed down to my grandmother and my mother. As did the rhubarb. My mother planted some of it in our backyard where, as rhubarb does, it grew and flourished.
When 
helloheather and I bought our house, we transplanted some of the rhubarb to our back yard. At first I wasn't sure it survived but last year it came back. This year, the growth has been strong and, for the first time, I harvested some. helloheather cooked up a strawberry rhubarb crumble that was simply fantastic.
The key to rhubarb, as I understand it, is size: small stalks make for good eating. Once the stalks get large, even though they're nice and red, they're very, very tart. Most people that complain about rhubarb have simply been eating the wrong things at the wrong time.
Unfortunately, I may have harvested too much. Research indicates that one should not harvest more than 1/3 of the plant at any given time. I harvested about 3/4 if not more. Most of it was very large stalks that I simply removed, but I realize now I should have left them. Hopefully this will not be the end of the plant and the wonderful crumble.