I think my least favorite scene in the whole trilogy was Willie Scott's song and dance number "Anything Goes."
I still to this day don't know what language Kate Capshaw was butchering up there on that stage, but my wife's mandarin Chinese and she can't understand a word of what's being sung. If it was Cantonese, it's still pretty unintelligible, but Cantonese wouldn't be the primary language used in a Shanghai club.
The scene is supposed to take place in the small "Club Obi-Wan" in Shanghai, but when all those dancers come out to do their thing, you see this gigantic stage accomodating close to 30 dancing girls. What's more, I suspect Spielberg ran some of the footage in reverse to make the girls do that move where they zip up off the floor and get back in line. Because "realism" is lost by these creative decisions, you're really taken out of the movie for a moment.
As much as I don't hate the characters of Willie and Short Round, they really weren't the greatest of sidekicks. I don't like sidekicks only because they tie the hero down with a limit on what he can do. It's better when sidekicks just meet people "at Omar's," letting Indy do his thing.
My honorable mention is, "Feels like I'm walking on fortune cookies!" Apparently the screenwriters thought that would be hilarious, even though the origin of fortune cookies began in the USA. A kid from Shanghai in the 30s probably wouldn't have any familiarity with them. At least during the dinner scene, Shorty didn't ask for "General Tso's Chicken."