I first saw this movie as a teenager when it came out in theaters, way back when. Seeing it again, nearly 30 years later, I was surprised at how well it has held up. The gags are still funny, the interaction between characters works great, and the cameos come off better than ever. (Steve Martin's has to be the best one.)

My kids (9, 11, and 14) all loved it, and the music is good enough that they are still humming the tunes many days later.

I would suggest that before seeing the movie, you should view at least a half-dozen episodes of the Muppet Show, to get a sense of the back-story behind the characters, otherwise the movie won't make all that much sense.