You know, Ive tried so many times to write this now. There are just too many. I will say, Jazz era the showtunes of George and Ira Gershwin are my favorites. Irving Berlin, Cole Porter, Leonard Bernstein, Sondheim also great.
A few names that have not been mentioned yet (or I just didn't see): James Taylor, Elton John, Paul Hewson aka Bono, Eric Clapton.
Having just started listening to some country, it was a real treat to see Don Schlitz and Bill Anderson play The Gran Ole Opry in October when they just reopened. Also found Brandy Clark, who is quite a talented writer and singer in her own right.