It should be noted that money laundering is a particularly difficult offence to prove. In particular, it must be demonstrated that the individual knew that the amounts they were dealing with were proceeds of crime. I think we could say that no country is very successful when it comes to this offence.
In Canada, we actually have two possible charges when we believe that an individual has committed a money laundering offence. In addition to the money laundering charge, we have a related charge of possession of property obtained by crime. We'll charge the individual with both offences, but the crown will drop the money laundering charge, which is much more complex, and keep only the possession charge. This charge is easier to prove, and the penalty is the same as the penalty for money laundering, namely, a maximum penalty of 10 years in prison.
However, to answer your question more directly, I can't think of any specific country that has been very successful in its money laundering prosecutions.