Waffling on this. It really should be Spanish but I couldn't roll an 'R' to save my life.
Rosetta Stone is tops in my opinion because it provides immersion, with no English, and makes maximum use of the senses. We have both Spanish and Russian. I am learning Russian becasue my family speaks it at home. They are learning Spanish, at which I am fluent.
Trilling the R's requires a bit of practice but not much. Practice making machine-gun sounds using a long sequence of trills.
By the way, I have the prior additon of Rosetta Stone Russian Levels I and II for sale if anyone is interested.