Where would you suggest a single guy spend New Year's Eve? I'm deciding between Auckland and Queenstown, but open to any suggestions. I'm thinking a bigger city would have more options, be more festive. Thanks.

Actually the best places, for someone young, are the smaller centres like Queenstown, Wanaka, Taupo, Nelson, Mount Maunganui, Bay of Islands. The main cities are relatively quiet at new years (many locals are away at a beach somewhere instead of staying in the city).