Where Do the Victims of the Death Note go?

[Kurosawa Kiharu]

They go in the world of death stare  

[xxmisashokuxx]

Haruna

Mu Ryuk says that Heaven and Hell don't exist and that all souls go to Mu.

That is incorrect.
Ryuk says, 'But, do not think that one who uses the Notebook can go to either heaven or hell' <---He just used those, didnt he?

And, in actuallity, one who uses the Note would most likely be sent to Purgatory, and then possibly to the Shinigami Realm.
Ryuk hints at this when he tells Light that he is 'already a fine shinigami' when Light jokes about the eye deal.  

[Starlight Mayberuu]

Limbo.

 

[jasonlei27]

also known as MU