quickest way to learn Japanese

I want to be fluent speaking in Japanese what's a quick and easy way for me to do so

Study.

What for?
Which level/skill needs?

For clear N1 or higher?
http://www.jlpt.jp/e/about/levelsummary.html
http://www.jlpt.jp/e/samples/forlearners.html

I just want to point out one thing when it comes to getting to fluency in any language. One of the most important things is to do something fun or that can keep you motived to get past the beginner stages of learning, so that you can really start interacting with the language.

The longer you stay within the beginner stages of learning a language the more you motivation will drop off. I know from my uphill battle with learning Chinese, I found myself perpetually stuck in the beginner zone, never truly able to pass into the intermediate stages of the language.

Also, chasing a lofty goal, such as, "fluency" will really kill your motivation to continue studying, because it is almost impossible to really feel like you have ever achieved it. While I keep in the back of my mind the idea of one day becoming fluent, it is not my driving force, since the goal is so far off it provides no motivation whatsoever.

The most motivating way I have found is to provide myself with little milestones along the way so that I can tell when I make progress. Because, after years of studying something, you will be hard pressed to figure out if you are making any progress at all unless from outside observers that notice the difference.

My current end goal with Japanese is to just read a newspaper article in all Japanese. Once I have reached that I will figure out where the next goalpost is and set my sights on that, based on my own strengths and weaknesses in the language at the time.

Now when it comes to studying, honestly it is just different ways for different folks. The only method I have found that keeps me motivated in my studies is Rosetta Stone. I have tried different books, CDs, YouTube Videos and even a video game back in the day (if anyone remembers "My Japanese Coach" for the Nintendo DS) and Rosetta Stone was the only thing that stuck for me. Don't let the price put you off, since that company literally has a constant stream of sales going all year long bringing the total price down to around $160 USD if I remember correctly. Honestly, it is a lot cheaper than classes and from my own findings it teaches quite a decent foundation for the later stages. (I'm currently at the end of Level 1 and moving on to Level 2)

Those are my thoughts on the matter, if you have questions about the programs and software I use in conjunction with Rosetta Stone feel free to reply on here or message me.

there is no one "quickest way" and anyone who claims to have it is probably just trying to sell you something.

everyone is different and as such we all learn in different ways. personally for me I found watching films/TV shows in japanese and listening to japanese music helped, combined with normal studies (about an hour or two a day) and even practice conversations (even if it's just talking to the mirror) to get used to speaking and thinking in the language.

some people find that just reading through language books work for them, others use flash cards, but the trick is to find what works for you, even if it's just learning every day phrases and translating things in your head each day when you're talking to people or walking around the shop

Here's what worked for me...

1. Formal lessons for the grammar and vocabulary
2. A close friend to practice with (talking, listening, writing)
3. Manga for the kanji, hiragana, katakana
4. J-drama for the conversation
5. Anime for the conversation
6. NEW Youtube language videos!