The Party Crashers (1998)

A gigolo, a former professional athlete, a spoiled heiress, a champion female figure skater, a live band, and three desperate men are all brought together under the same roof, for a party thrown by a young, hot-shot, corporate attorney. The three desperate men are good people forced into crime by their own personal circumstances. Knowing that the heiress will be present, they crash the party and hold dozens of guests hostage. They demand ransom from the heiress' father, a powerful publishing magnate, warning him that if he goes to the police, he will have the blood of countless innocent victims on his hands. This being Los Angeles, of course, no one at the party is really "innocent". The former professional athlete and the gigolo are morally corrupt men whom circumstances force into heroic behavior. They courageously attempt to foil the kidnapers' plans and liberate the guests held hostage. Unfortunately, no one at the party turns out to be quite what they say, and everyone has their own unique agenda. It's a party no one will ever forget, with live music, catered food, a fully stocked bar, several felonies, and a host prepared to capitalize on any eventuality.