CTMA is ok although not many stores these days but walk around to Sino Plaza (Animate in the basement often have a decent stash of MP's and the Hot Toys showroom is a MUST VISIT! - Check which floor as you'll have to take a lift up) and then down the road to Ins Point (near Yau Ma Tei MTR but walking distance from Sino and CTMA). Ins Point is Transformers/Lego heaven both from a window shopping and "actual" shopping experience. There is also a fair bit of vintage stuff there although most of these places know their worth so don't expect bargain basement prices. Most important thing to remember with Ins Point is don't bother going before 3 pm (and in fact some places don't open until 5 pm).