Personally, because of the diversity, I'd still rank the US number one, but having lived in various places around the world and travelled in many, I'd have to add few:
1. France, particularly way outside of Paris, where lunch can be incredibly economical and heavenly. As much as i hate to, i have to give them the number one spot
2. Northern Italy, especially Tuscany.
3. Spain, almost anywhere, but you have to find the spots.
4. Barbados......a surprise, and not just among the Caribbean countries! Some are inexpensive, some wildly expensive (especially dinner), but almost consistently good.
5. Taiwan,,,,,i haven't been to China, but in every restaurant I ate in Taiwan.......fancy or austere... the food was fantastic and fresh.
for bonus points, you can also list a few of the worst countries. Can't say i was thriled with Denmark for the price/taste trade-off.