[ChisaChi]

I agree with the general consensus - Japanese media might be good for some degree of listening practice and for picking up random words, but when it comes to learning a language properly to a useful extent it really isn't enough.

I'm an anime fan and in my second year of studying Japanese part time, so I can relate to people who find the stiltedness of -masu and -desu forms a bit frustrating and hard to relate back to anime or the way Japanese friends speak... but those formal forms give a solid basis that let you easily convert to other forms, whereas if you start straight from plain form it would be harder to make it more formal, I think. It helps a lot to know the rules and structure behind things rather than disjointed words and phrases without any background.