There are almost always fireworks in the harbour at midnight. Not sure if some corporate group has stumped up yet this year to pay for them, but I would assume that is the case and plan accordingly, so you can either be outdoors or indoors with a view at midnight. (Getting a harbour view hotel room could be a very good use of money for NY Eve, IMO. Note that in the past, the fireworks have been shot off from near the IFC Building, rather than from the middle of the harbour as si the case on on Lunar New Year and July 1, so not all harbour view rooms would necessarily have good firework views on December 31.)

On NY Eve you may want to stay on the same side of the harbour as your hotel, just to avoid having to travel, as cabs may be scarce and public transport can be crowded. If you can walk from place to place, so much the better IMO. If you can tell me where your hotel is, I could provide more specific reccos.

I agree with your notion of eating dinner early so as to avoid the higher fixed-price menus you will find in hotels and virtually all restaurants on NY Eve here. Your choice is almost limitless in terms of cuisines and prices. Do you have a preference for cuisine? Even for an early dinner, I think I would suggest a reservation, unless you are going to a casual noodle place.

Bars like Sevva, Felix, the Intercon bar, and the bar at Hutong will offer views and can be fun places for a celebration, but I am not sure what they are requiring in terms of booking and minimums for NY Eve. Tott's, on top of the Excelsior Hotel, probably would not work for fireworks, but is a fun bar and has an outdoor terrace with nice views generally. There are also a number of restaurants/bars in the new building called The One in Kowloon which has views, I have not been to any of them yet, see http://www.the-one.hk. I really like the view from FoFo, a Spanish restaurant, it is not the classic harbour view, but is a nice little bar and they have a lovely rooftop area with sofas (the restaurant there is also terrific). I know that Felix has a somewhat steep cover charge for NY Eve, and I believe the others are the same. You might try their websites or try calling them. (Sevva would have to be outdoors for views.) Again, sticking to the same side of the harbour as your hotel would probably be the best idea.

Otherwise, if you don’t have a harbour-view room, then go to an outdoor spot to watch the fireworks. Both sides of the harbour are good spots, these will be crowded but should be liveable. You may have to go about 2 hours before to get a spot. You might consider joining a boat tour, or if the Hutong’s junk is making the trip go on that, as watching them from the water can be very pretty. (Dress warmly it will be quite cool to actually cold.) I actually think that the Peak is a great place to watch them from, again if you are not at a restaurant (Pearl on the Peak would be my choice), I would walk out along Lugard Road or go down to Baker Road (I can give some directions and some other thoughts if you want to e-mail me at cicereonehongkkong@live.hk. I can also provide contact details for the restaurants.) The top viewing deck of the Peak Tram station would also offer good views. The one drawback to the Peak is getting back down after midnight, the #15 bus or #1 minibus are your best choice, but there may be lines. (The Peak Tram would be quite mobbed I believe and should be avoided.) Taxis are hard to find on NY Eve, like many places but very convenient if you can get one. Perhaps pre-book a taxi to pick you up at a set time after midnight.

If there won’t be fireworks, or if you don’t care whether you see them (which IMO you should try to do), the main non-view areas to celebrate would the Lan Kwai Fong bar area in Central (younger crowd, under 30’s) SOHO/Hollywood Road area also in Central, or the Times Square area in Wan Chai. There are dozens of bars in both Lan Kwai Fong and SOHO, most of them open to the street, so there is a real party atmosphere. I don't think I would recco just one. There is a countdown at Times Square (but really not a lot of bars or pubs, the closest would probably be the Crowne Plaza hotel). These all can be really really crowded, esp Times Square. It’s like Time Square in NYC without the drunks. There is a bar area in Knutsford Terrace in Kowloon which might be worth a try if your hotel is in that area. The Kowloon esplanade and Victoria Park area may also have events (have not ever been to those areas for New Year’s so can’t speak from experience).