"To sing for you" by Donovan includes a V chord (G). And the fingerpicked "Freewheelin'" version of Girl/North Country begins by going from G to a 3-finger C (sixth string is picked open) position on the third fret. Don't think that is an actual chord, but I watched him play it and that's how I learned it. And the V chord is a D9. As to the original question, I don't know any songs that use just the I and IV chords.