I'm a fan of Jerry Lewis. Here are what I consider to be his best films.
That's My Boy (1951) with Dean Martin
Money from Home (1953) with Dean Martin
3 Ring Circus (1954) with Dean Martin
Living It Up (1954) with Dean Martin
You're Never Too Young (1955) with Dean Martin
Artists & Models (1955) with Dean Martin
Hollywood or Bust (1956) with Dean Martin
Visit to a Small Planet (1959)
The Bellboy (1960) first feature as a director
The Errand Boy (1961) also as director
The Ladies Man (1961) also as director
Who's Minding the Store? (1963)
The Nutty Professor (1963) also as director
The Patsy (1964) also as director
The Disorderly Orderly (1964)
Which Way to the Front? (1970) also director
The King of Comedy (1983)
Lewis also directed (but did not appear in) One More Time (1970), a sequel to Salt and Pepper (1968) starring Peter Lawford and Sammy Davis, Jr. The Lewis film is the better of the two, IMO. Lawford and Davis play to swingin' detectives caught up in murder and mayhem. The film features an amusing scene in which Sammy opens a door. He steps through, and finds himself in a Gothic castle, complete with Dracula (Christopher Lee) and Dr. Frankenstein (Peter Cushing). Sammy does a double-take, turns and runs back through the closet, where he gives a perfect Jerry imitation, sputtering, and trying to convince Lawford of what's on the other side of the door. Of course, when Lawford opens the door, there's nothing.
Jerry also is sitting on a controversial, notorious never-before-released film that is very close to his heart: The Day the Clown Cried, which was completed in 1972. Set during WW2, Jerry plays a clown sent to a concentration camp, where he entertains the captive children. There are a variety of stories why this film was never released. Probably the most realistic one is Jerry took the script (and concept) from the original writer and re-wrote the screenplay to suit himself, which upset the original writer (I believe the writer brought a lawsuit against Lewis). The film was rumored to come out over the years, and a couple of filmmakers in the 1990s attempted to "remake" it, using Jerry's rewritten script. But so far, nothing. The film remains a sore spot for Lewis, who is still upset his "masterpiece" never saw the light of day. Some who have seen it in private claim it's awful, corny and laughably bad. Who knows? It still sounds like an interesting curiosity, especially amongst Lewis fans.