You may want to check out: First choice: Drai's Night Club/Beach Club at the Cromwell (The former Bill's/Barbary Coast). This would be a great place to watch the fireworks. I think the party runs from 10pm - 4am. Men $100 Women $50. Very nice club and Beach Club is on the roof center strip. This place is very new. (not open bar).
http://draislv.com/?gclid=CJXnisf618ECFdKIfgod62QAlQ
2nd choice: Foundation Room on the top floor of Mandalay Bay. Another great place to watch the fireworks. (not open bar). Now that I think about it. This may only be open to members.
3rd choice: Voodoo Lounge at the Rio (top floor) or Ghost Bar at the Palms. Again, this is if want to watch the fireworks.
There are tons of parties on and off the strip. Many concerts, including a unique one: Tony Bennett with Lady Gaga. There is also Maroon 5, Justin Timberlake and many more. If you do not care about the fireworks, look for your favorite DJ or Band. Some charge more but may have an open bar.
More info:
http://www.lasvegas-how-to.com/new-y...-las-vegas.php
One of the best dining spots currently is GIADA, but for New Years Eve I am sure they are sold out. Morels Steakhouse I have not been to.
Have a great visit! ^