If you don't enjoy dressing up, skip the formal night. Alot of people REALLY enjoy it (some go a bit crazy with long gowns and tuxes but hey, that's their thing and they enjoy it). Others wear a cocktail dress and the guys wear at least a jacket and tie. My teenage boys just wore a shirt and tie with dress pants and dress shoes and that was fine. HOWEVER, going extreme the other way with jeans or something like that kind of ruins formal night for those people that do like to dress up, so if you are one of those people, just skip the formal night. Why go through all of that if you don't enjoy it? It really does ruin it for the people that like formal night when they go through all of the trouble to dress appropriately and others don't. Just my two cents...