I find most foods are best as soon as they are made, but some things seem to get better when the flavors have more time to meld. The only two I can think of right now are chili and hummus. What other dishes am I forgetting, or haven’t tried that you think get better with a little time?
Lasagna is pretty universally agreed to be better as a leftover. Non-pasta soups are usually better too. I have a sausage, potatoes and pepper hash I make that is mostly a excuse to have it with a fried egg as breakfast in the morning