Why does Ryuk love apples? It is often seen in Death Note that Ryuk loves apple. Why is that? Do all Shinigami (Death Gods) love apples, is it the only food for Death Gods or does he just love apples? 

Also.. Is it to signify the apple as the forbidden fruit?
If I remember correctly, Ryuuk said that apples in his world were dry and awful, but in human world they were "Juicy." 

This is most likely the reason why he enjoys apples. There's also probably some hidden meaning to it.