bangkok, hanoi or manila come to mind

I agree on the above. I would also add Singapore, which is ideal for a long weekend and completely different from Hong Kong (other than both offering superb public transport). In the PRC, consider Guilin, Kunming/Lijiang, Xian, Xiamen, Shanghai and Beijing (for a small taste of the later as there are so many tourist sights). Bali and Phuket/Krabi should work if you take non-stop flights; again it would be a small taste of Bali but a little bit is better than nothing, IMO. Luang Prabang and Ankor Wat would work very well for that short a trip; however there are no non-stops from Hong Kong as far as I know, so you have to see if flight schedules work for you. Kuala Lumpur would work, it offers less in real tourist sights, and is more about eating and wandering some parts like Little India. Beach resorts on the east coast of Malaysia like the Redang area would be lovely now (and even better in April), again you have to connect via Singapore or KL so a long weekend may not be the ideal way to see these islands. Sanya on Hainan Island would be easy to reach via a non-stop (1.5 hours) and has very nice beaches (temps a little cool now, but if you mean Easter then temps will be better).

For some of these, you may be better taking off the Friday and then returning Monday morning, as flight times could work better.

You could also consider a long weekend in Macau, I would say more at a beach resort like the Westin as opposed to a city hotel (or those awful casino hotels).

Taipei is close, with cheap and frequent flights.

Thanks for the suggestions.

I will be travelling on my own so obviously safety plays a key part in making my decision. I've heard good things about Boracay. I think i have to take a plane to the phillipines and from there get another flight to Boracay....does anyone know if that sounds right? Also, how long is the travel time? Prices roughly?
Mnay thanks

When I lived in Hong Kong I often had the same challenge. Sometimes we'd just pick a ferry at random and spend the weekend in town on the Pearl River Delta.

I've been to Boracay several times (though not recently). As I remember getting there was not so easy. I wouldn't recommend it for a long weekend.

For urban you have lots of choices -- Hanoi, Bangkok, Singapore, Tokyo would be my top picks.

For beach or countryside I'd consider Phuket or Bali. They both have sophisticated tourist infrastructures, so once you arrive you'd settle into the holiday mode right away.

Are there cheap flights from Hong Kong to Bali? The cheapest flight I can find in September is 500 dollars!

HK to Philippines plane rate is usually $800 HK one way. If you can catch some promos then you can get it for as low as $350 HK.

Be careful of the Phillippines in September, that is right smack in the middle of typhoon season. Even if you don't get a tyhpoon, you can have lots of rain. See weather websites for an idea. The Phillippines are better for beaches from November through May or so.

Not sure how one finds cheap fares to Bali. As you are in Hong Kong, try with some of the local tour agencies here, they sometimes offer deals. Cathay Pacific sometimes has promotions as well.

From HK you can get to Bali cheaply if you create your own itinerary using the low fare carriers. For example, Jet Star to Singapore, then transfer to an AirAsia flight to Bali. The problem if if one flight is delayed and you miss your next flight you aren't protected, and your luggage isn't checked all the way through. Air Asia is a point to point carrier - you have to make your own itinerary with connections. We went from HK to Kota Kinabalu ($200 RT) and then from KK to Sandakan ($45) RT for a total of less than $300. If we had priced out HKG to Sandakan, it would have been close to $1000. You have to get creative.

I think Bangkok is a good bet. Plenty of direct flights from HK - 3 hours.