I've found similar posts really helpful in the past..... which toys did you buy last year which are still being played with? The age of children might be helpful to guide others with their shopping too....
My DD(3) (but 4 at Xmas) has grown into the Barbies I bought her last year which she was disinterested in at that point. Also, her plastic glasses and handbag are also still proving to be hits...
My DS(6) is still playing with his Lego and playmobil but it really is the vehicles which are more of a hit than the police station...