Universal CityWalk throw a huge party on New Years Eve with entertainment including bands, fireworks, food and drinks. This is an all ticket event & strictly over 21.
Islands of Adventure & Studios close early to allow for the party preparations.
We found that lots of hotels & restaurants had 'ticket only' parties but all were strictly over 21 as free alcohol was part of the package.
As mentioned in our previous thread we would recommend Planet Hollywood for a party atmosphere - especially for teenagers!
Steve & Jeanette