Three boys here, ages 3,5 and 6 and here's what's been a hit over the years:
-little cars
-big trucks like tonka
-wooden railroad and trains
-airplanes
-wooden blocks
-anything toy story related (especially a V-Tech phone that DS 3 plays with every single day)
-anything cars related
-a gigantic plastic box of legos that Ì bought at a rumage sale and wrapped - they play with that everyday
-bikes, helmets, plastic red and yellow car for toddler (they've outgrown it, but they played with it all the time)
emote-control cars
-transformers
my middle son is a little different, he tends to like craft supplies, jewel making kits or even boys' necklaces, Backugan stuff
my oldest loves memory or puzzle games and activity books.
my youngest loves Zhuzhu pets and could play with them for hours.
They always love to receive cartoon DVDs, especially if we've seen the movie at the theatre. Mario Cart, Super Mario and Kirby were huge hits, too.
They also like trying new candy, cookies or drinks so I stock their stocking with that. Stickers, lip balm, polished rocks
are all appreciated too.