Two bright red tomatoes that were being washed clean under a stream of fresh water. Currently, tomatoes are one of the most popular vegetables eaten by Americans. Tomatoes are members of the fruit family, but they are served and prepared as a vegetable. This is why most people consider them a vegetable and not a fruit. Tomatoes are an excellent source of vitamin C and a good source of vitamin A. There are thousands of tomato varieties. The most widely available varieties are classified in three groups: cherry, plum, and slicing tomatoes. A new sweet variety like the cherry tomato is the grape tomato, really wonderful to eat alone or in a salad.