I'm looking for a database of stars that lists as many of the known stars as possible. Ideally, I'd like it to have information on the radius of the stars, the distance from the earth and the classification. What source(s) exist for this data (preferably in a simple form)
One possible such dataset is the HYG database.
120,000 stars, has the properties you listed, and consists of a single CSV file.
One possible issue is what you mean by "size". HYG has the absolute magnitude of stars, but not mass nor radius.