Other than RID2015 Megatronus (for my son) from AU TRU I've bought many a figure from HK Toys'R'Us which, while expensive by local standards, sometimes have some great deals or freebies with figures or run Hasbro Transformer events which might be why it and the Asian sector of the franchise remain so robust.
The other good thing about the HK Toys'R'Us is they generally get their stock in a week or month after the figure is released so you're more likely to find that one figure that sold out the day of release suddenly pop up on their shelves.
For a lot of people who don't know about the smaller local HK toy dealers, or don't want to think about where to source toys, or those too scared to go to the "dark side" of HK (yes people there really are those who live in HK who don't go to Kowloon unless in transit to the airport) Toys'R'Us is the only major toy store chain in HK to source things from and they don't have department stores (a la Target, K-Mart, Big W, The Warehouse) to contend with so they remain both popular and successful.
My first Official collectible figure - Year of the Horse Optimus Prime came from HK Toys'R'Us so I do have a bit of a sentimental spot for them.
I've also got a number of collectable figures from them over the years - Battle damaged The Last Knight Optimus, Barricade and Bumblebee, The black box Slug from AOE, pewter Optimus Prime mini statues, numerous RID2015 figures (and freebies like crayons and folders) for my son as they'd often run discounts, 2 for 1 sales, etc on them, Hasbro MP Grimlock, Combiner Hunters boxed set, Seige on Cybertron boxed set...
Ah - good times.
Prior to becoming a Transformers collector, while living in Sydney before our time in HK, Chatswood Toys'R'Us got a lot of visits from us when our oldest was a baby/toddler because my husband finally had an excuse to buy toys and her first Optimus Prime came from there when the 2007 movie came out.