It's hard to resist Gene Kelly as a former GI trying to make a go of it as an artist in An American in Paris. Plus the movie's pretty much one big Valentine from Hollywood to the City of Light. But although I'm a complete sucker for old time movie musicals, I always cringe a bit when I watch that big production number ballet at the end, the one supposedly set in the Place de la Concorde. Far better, and in fact, filmed on location rather than a Hollywood backlot, is the photo shoot scene from Stanley Donen's Funny Face with Audrey Hepburn and Fred Astaire. You can skip the rest of the movie; the story is silly, Astaire did better work elsewhere, and there's a reason why Audrey Hepburn's singing was overdubbed in her next musical, My Fair Lady.
Just enjoy. (Fast forward to 2:10 where the real fun begins.)