Was Adolf Hitler Insane?

Fortunately, we have access to thousands of captured documents secured after the second world war. For a very detailed general history of hitler and germany i recommend shirer's 'the rise and fall of the third reich'. The absolute best book out there on hitler to satisfy your specific question is 'a psychopathic god: Adolf hitler' by waite. It is the only publication offering a strictly and very rare psychological profile of the man. It is objective and the author specifically states any speculation or opinion not based on fact. For example, wait offers that there is speculation that hitler might have been under a psychiatrists' care at one or more times throughout his dictatorship. However, he first states that there is no empirical evidence to support those speculations. Yes, he was megalomaniac, egomaniac which might lead the reader to believe he was too proud or arrogant to think he needed one. On the other hand, as intelligent as he was, he also suffered from doubt and indecision which might imply that he did see a doctor if for no other reason than to reinforce his own egomania. After all, even if hitler did see one and even if he told him to be honest in diagnosis, would the doctor be so foolish to attribute any mental defect to him? He'd undoubtedly have been shot! Anyway, it's a fantastic book and it really opened me up to have a more understanding perspective of the man. I read it first, then read 'the rise and fall...'. I had a much more interesting and 'tolerant'(?!) journey through 'the rise...' because I felt I knew more about the whys of hitler's actions and behaviors. If hitler was ever given a psychiatric diagnosis during his life a chemical imbalance in his brain would bring shine a bright light onto why he was who he was. Yes, he was a very cruel, thoughtless, selfish, egotistical, etc. Person but I believe objectivity, when interpreting history and its' makers, is essential to full understanding. I don't mean to offend anyone when I say this, but I really get irritated and frustrated with people who say hitler makes them angry and disgusted when they hear his name. To them I say 'contempt prior to investigation'! I want to be factual or be able to admit that I'm not sure or simply don't know rather than rest my laurels on hearsay or my own ignorance.

Hitler is definitely not insane.  How could someone insane make millions of people believe to his  ideology.although , scientifically based  his maniest personality falls squarely within the meaning of insanity, still, its not applicable to all, sometimes science cannot deal with certainty and particularity, most of the time it generalize its application. Considering that hitler has odd character its doesn't mean he's insane.

Of course he is insane

Some people believe so. Personally no one is really insane but they are just not able to realise their actions.

Oh yeah, insane for power

My first reaction to your question was No, but after checking the def. Of insane, I think that is a pretty accurate description.  A psychiatrist would have to make the official determination, of course.  I have read about Hitler quite a bit and Stalin even more.  Stalin was insane in my opinion to a much larger degree than Hitler, because Stalin acted many times just to satisfy his ego even when it put Russias at great risk.
Hitler was much more intelligent than Stalin, but he used his intelligence to develop some very warped opinions and philosophies.  Some say there is a fine line between genius and insanity.  Hitler crossed the line for sure.
But while both Hitler and Stalin were egomaniacs, it was Hitler's ego that ended up causing his defeat in my opinion.  Both of them ignored the military advice (pleadings would be a better word) of their Generals and tried to use their own tactics.  Hitler's strategy brought Germany to its knees and from what I have read his generals slowly began to ignore his orders because it would have totally destroyed their country.
I think Stalin's military did the same thing but they had to do it very carefully because if Stalin summoned a general to Moscow, it was usually a one way journey.
These are just some opinions I have developed from reading several books.  I don't claim to know any more than any one else.