I am astonished no one has trolled this with Shakespeare yet, apparently my opinion of CD is undeserved
In addition to British writers I'd suggest watching some British telly, that way you can pick up on the cadence and accent as well. Not that excellent dialogue can't be achieved in written works but at the very least it can't hurt to hear it. I don't know how accessible British television is in Hong Kong even though it's a former colony, but if you can grab something like Midsomer Murders or a Brit Com I'd highly recommend it.
Is Midsomer Murders the best of our telly you get over there? That's depressing...
I'd just like to throw in China Mieville as a suggestion, especially his book "Kraken", which is set in modern day London and is one of the best books I've ever read. Most of his other books are set in fantasy worlds, so although they're fantastic they probably aren't exactly what you need.