Since elemental Vitamin C seems to go right through me, I'm always on the search for nutritional options.  This is a pretty good overview of different C-rich foods.

I love mangos but when they arrive in our stores, they are as green as an overgrown brussels sprout and if I buy them green and take them home, they just rot before they ripen.  It's frustrating.  Also, I love oranges but not naval oranges which are often as dry as dust.  I like Valencia oranges but they are only available here for about 2 months and often when we get them they are under-ripe, so I'm not sure what the nutritional value actually is, if any at all.

https://www.tasteofhome.com/collection/food-with-vitamin-c/