Rosetta Stone is not the best program that is out there. The problem with it, is that it is designed for how children learn languages, and as adults our brains do not pick up language at the same rate.
Specifically it doesn't teach you grammar rules, and neither does pimsleur. Rosetta uses pictures and gets you to listen to speech so you work it out yourself. Pimsleur works by getting you to imitate examples of native speech and make variations in what you are imitating.
I am a big advocate of learning in multiple ways and I think you do need grammar lessons and word definitions. You could get that by working through a good instruction book and doing written problems. Also I like flash cards for vocabulary building.
I really think if you try to find one system that will do it all there isn't one.
When I was seriously learning a language I took a night class, I used pimsleur, I used Rosetta, I practiced with flash cards, and I tried to use it every chance I got. I was also married to a native speaker. I didn't do all that every day but I did something every day and kept changing it up.
When I pick up some language for traveling to get by in another country but not trying to achieve fluency I find pimsleur great for that.