If you want your skin to look better, what is the best food to eat?

First off, WATER
Plenty of water!

From your display picture I'm guessing you like tea ^_^, that's a start

Plenty of water.

Drink - If you haven't guessed already lots of water

Eat - A good balanced diet that includes lots of fruit & veg

Lots of water, fruits, veggies and lean protein

I suggest you load up on any fresh berries. They are all high in antioxidants. Remember you need foods that are rich with vitamin C and E. I also recommend the Mediterranean diet. Stay away from the sun, it's damaging to the skin and make sure when are out in the sun, use a sun screen. What's also damaging to the skin is stress. If you use make up, make sure that you buy the more expensive brands, they really are better for your skin.