Barring the blended-nation type ones (America) which is kind of cheating, I'd go with French. Northern France has the heavier northern Euro style cooking, the south has lighter Mediterranean style cooking, they have a wide variety of seafood, cured meats and sausages, they are legendary for their desserts, cheeses, pastries, breads, and their liquor selection is second to none. French cuisine isn't even my favourite at any given time, usually but it's a really complete package, and a spectacular mixture of variety and quality. Pretty much every nation I've seen listed here has great strong points - some very strong points - but lacks in some major area that France is strong in. I can't think of any non-modern nation whose cuisine is even close to having the wide variety that France does. Strong point against it though is limited use of spice - as in, heat - compared to other nations.
