Unfortunatley, most of the bars now have the standardized menus, which really eliminated a lot of the original specialized drinks. For something different I like Dad's Electric Lemonade at the Tune Inn Lounge (Prime Time Cafe).
Although not on the menus, if you can get someone to make them for you try the Tradewinds at the Tambu Lounge, Oreo Mintini at the Marthas Vineyard Lounge, Nyami Nyami at the AKL pool bar, or Space Monkey at the Outer Rim Lounge.