The ones we never heard of are the greatest because they are practicing the highest form of tzedakah.
I read a children’s book when I was young about a rich man in town who was known for being stingy. Schools, shuls, and other Jewish organizations would approach him for money year after year and he wouldn’t give a cent. Eventually he died, and that week the soup kitchens were inundated with poor people he had supported without anyone’s knowledge.