I like all the group and Simon solo songs mentioned, although surprisingly no one has listed "The Sound of Silence" yet. Other, slightly more osbsure excellent ones form the brilliant pen of Paul Simon (who IMHO has the higheset "batting average" ever of any pop writer. along with Tom Petty) are "Hazy Shade of Winter," "Fakin' It," "You Don't Know Where Your Interest Lies" (which was unavailable for 30 years), "The Only Living Boy In New York,' "Mother and Child Reunion," "Duncan," "Me and Julio," "Was A Sunny Day," "Late In The Evening" and many more. Also exqusite is Art's hit remake of "I Only Have Eyes For You."
Is everyone aware of the incident during the first Central Park concert when a deranged fan jumped on stage during "The Late Great Johnny Ace' (with its Lennon assassination reference)? And that Paul's "Thanksgiving turkey" appearance on SNL occurred on the same 1976 show when he duetted with George on "Here Comes The Sun" and "Homeward bound," along with several others that weren't broadcast? Unfortunately, this ultra-classic performance has not seemed to appear on any video retrospective since the early 1980's.
(BTW, the lowest "batting averages" of writers with any talent are from Neil Young and Ray Davies, who have both pumped out 10 - 20 more material than they should have, artistically speaking.)