Simple as: taste great, can be made into several different foodstuffs, can be grown easily by the thickest idiot, hundreds of varities, and very cheap. No food is as useful and practical, and I doubt I'll find competition for this except rice or wheat which I'll have counter arguments for anyways.

How about oats?

i think it's chicken nuggets tho

Good luck growing Rice and wheat in your back yard by accident. That stuff takes time and effort unlike potatoes that once they are in the grown are boarderline a weed... I very tasty and awesome weed.

So no I will not debate you on this. All hail potato!

Potatoes being the best is a universally accepted fact, but the true argument lies within HOW potatoes are served. For me, it's simply baked potatos.