I was disappointed with Pacific Place decorations this year. Seems like they downsized them. But "bells" is a nice theme. The Santa picture is great and so is the Santa.
Much better than the Landmark Santa picture, which is really, really small. The Santa was nice, though.
Never really like the Ocean Terminal decorations. This year their theme seems to be "purple". Not a Christmas color where I come from.
A little further north is Festival Walk (Kowloon Tong). Nice Santa with a great frame for the picture and only HK$50, if memory serves. Decorations, this year, are a little more classical. And they have the (fake) tree that stretches to the ceiling of the mall. Lots of garland around the mall.
But it will be up to your tastes, really.