I wouldn't say that anime is a great source to learn from, especially as a beginner.My main reason for watching anime is simply because I enjoy it. However, picking up commonly spoken words is definitely a bonus. For example, I've frequently heard anime characters say "chigau" to tell someone that they're wrong, or "daijoubu desu ka" to ask if someone is okay. When I learned these words in Japanese class, they were very easy to remember because I basically already knew them. This applies to a myriad of different words I've heard in anime. I believe that it can be a very good supplement sometimes. Aside from its usefulness in learning Japanese, anime is probably the biggest reason I decided to take the language. It was somewhat of a pipe dream to be able to one day understand an anime episode or a Japanese song without any subtitles. I'm not sure if I'll get there, but it's still my main goal in Japanese.
