If you are married then yes I agree with the above friend, red envelope ( lai see ) is the best cos then their mom can buy whatever she wants for her kids but second to that for for those single non married friends I reckon toys are the best. Clothes, kids tend to grow out of them vey quickly but toys are fun for all ages.
Depending how much Toys R us is the best for toys and you can check out Babies R us their which sells loads of toys for babies.
As for ideas, educational toys are the best. They are fun while they are learning from it too. Fisherprice has a good range and so does Playskool, Vtech and Leap frog.
At the moment, I have my eye on Leap Frog Magnetic alphabet, selling at Toys R us with a discount at HK$159 ( orig HK$199 ). If you can't find Toys R us, you can go to Sogo, Jusco, and other big department stores as well.
Have fun shopping for toys.
參考: check out toysrus.com.hk or fisherprice.com.hk