Whhoooo! Get ready for a PARTY!! It's jammed at NYE. Our favorite place to be is EPCOT. Loads of different things going on, readily accessible champagne and to a certain extent, less of a crowded feel.
Although, there have been years when its been so crowded we had to leave. Hopefully, you'll have a great time!
Get to whichever park you choose early though. They do fill in fast, and WDW has been known to shut the gates to newcomers if the parks get too full. Happened a couple of different times when we were there.
Trust me. You may not want to be in EPCOT when it reaches capacity! Shoulder to shoulder people!!!!