“It’s the Girl” from the 1981 PENNIES FROM HEAVEN. It’s mimed (as are all the songs in the musical), but Steve Martin and two guys you’ve probably never heard of, Steve Rall and Robert Fitch, dance up a storm:
youtube.com/watch?v=fXgmZdYfD34
Chris Walken trained as a dancer before he became an actor, and includes some short dance moves in every film he’s done. His “Let’s Misbehave” may be a little ribald for this site, but I’ve always liked the film he did with Sean Connery’s son of “Puss in Boots” as a guilty pleasure (Walken played the cat.) Here he is singing and dancing to the song, “Happy Cat”
youtube.com/watch?v=GEjKmsMkPKQ. Not a “movie” per se, but his dancing in the music video to Fatboy Slim’s “Weapon of Choice” is a delight:
youtube.com/watch?v=wCDIYvFmgW8
Always liked this number from KISS ME KATE featuring Carol Haney and a very young Bob Fosse, before he became a choreographer and director. You can see a lot of the classic smooth Fosse dance moves even then:
youtube.com/watch?v=qw0FSREoaLQ
Also liked this Mambo he and his then-wife, Gwen Verdon, did for D*MN YANKEES:
youtube.com/watch?v=BIiZuAVZH4w.
And the Mambo scene from WEST SIDE STORY:
youtube.com/watch?v=kokbJvSEMUY and “Cool”:
youtube.com/watch?v=wugWGhItaQA
And “All For the Best” from Godspell - here’s a short clip:
youtube.com/watch?v=QL6d0ASmvfs (Always wished I could have seen the Toronto cast of Godspell - Martin Short, Gilda Radner, Victor Garber, Eugene Levy, Dave Thomas, Andrea Martin, and Paul Schaeffer as musical director…)
And Mikhail Baryshnikov dancing to Vysotskii’s “Horses” in WHITE NIGHTS:
youtube.com/watch?v=–LbFRO8SQQ