https://variety.com/lists/peanuts-holiday-specials-ranked/a-charlie-brown-christmas-1965

A Charlie Brown Christmas tops this list from Variety because it still strikes a chord after 55 years.

1) A Charlie Brown Christmas (1965)
2) It's the Great Pumpkin Charlie Brown (1966)
3) A Boy Named Charlie Brown (1969 - feature)
4) Charlie Brown's All-Stars (1966)
5) You're in Love, Charlie Brown (1967)
6) Snoopy Come Home (1972 - feature)
7) He's Your Dog, Charlie Brown (1968)
8) It Was a Short Summer, Charlie Brown (1969)
9) Play it Again, Charlie Brown (1971)
10) A Charlie Brown Thanksgiving (1973)

IMHO the mellow 70's specials/films are not up to the pure comics-inspired 60s specials and first feature - where CB is an unmercifully tortured soul and Lucy is at her worst.