There are probably 5 different types of malls:
Luxury malls - IFC, Elements, Harbour City - these are catered to hordes of tourists from mainland china, and possibly the occasional HKer
Youth malls - APM, Langham Place, Popcorn, WTC - these are catered to young people. They have slightly more interesting things to see, and you might actually buy something there. However in recent years these have begun catering more and more to mainland shoppers, and the more interesting stores are being pushed out in favour of luxury goods and herbalists.
Small Youth Malls - similar to above, but usually tiny malls with narrow hallways. These have the most unique, independent stores, and are one of the few mall types that aren't taken over by the same chain stores all the time. These are found throughout all of HK with quite a few in MK
Normal malls - Telford Plaza, Festival Walk, Metroplaza, etc, etc, etc. Basically one at every MTR stop, each one pretty much exactly like the other.
urban malls - too many to name, always have chinese names (Kai Tin, Lung Cheung, Hau Tak, are some I can recall OTTOMH) - also near every MTR and urban area are smaller malls with some smaller stores, usually a grocery store, some independent clothing stores, pharmacies, etc. They usually have a wet market on the ground floor, and sometimes a public food market. These are sometimes connected to the 'normal malls'.
Not sure where Megabox fits into the spectrum.. it seems to want to be a 'youth mall' but aside from the design, there aren't many stores to shop at. It used to have a B&Q (british Home Depot) and a huge craft store but as if HKers are interested in renovating their own homes and making their own crafts. It's now an Ikea and some furniture store. It looks cool, but IMO not worth going to, especially since it's not especially convenient. I used to go there after gym every day for a great deal at a viet restaurant, but the quality went way down and prices went up
If you're visiting, you will probably only be interested in the luxury malls, since they can be for sight seeing as well, and the youth malls. You might check out some 'normal malls' too since you can get good deals sometimes. It might be more interested to check out the individual shopping areas.. MK for electronics and cameras, SSP for computer stuff, CWB for fashion, The small urban malls are more for day to day living, but if you are in need of cheaper restaurants, pharmacies, etc, then you might end up at one.
I have NO idea why I wrote all that, especially since I am suffering from writers block when attempting to work, but there ya go
