Ironically, this is one subject which has been very well served by books....
The three major Allied powers went to the most extreme lengths to verify the story of Hitlers death. For the British, H R Trevor-Roper was first in the field with
'The Last Days Of Hitler', for the US, Musmanno interviewed Bunker survivors ( information used by O'Donnell in
The Berlin Bunker ).Stalin went to almost insane lengths to establish the facts ; the Soviets had captured several key Bunker witnesses including Gunsche, Linge and Baur. These witnesses suffered lengthy imprisonment and extreme psychological pressure. A personal dossier for Stalin was prepared using the results and this has only recently been published under the title
'The Hitler Book' with an introduction by noted historian Richard Overy. There is also an excellent overview of all earlier sources ( including Bezemensky and numerous others ) in Anton Joachimsthaler's
'The Last Days Of Hitler - The Legends, The Evidence, The Truth' published in 1996.
Basically, all the witnesses agree, and none of the major facts as cited by Trevor Roper have been seriously challenged ( and don't forget that at one point the Soviets very much wanted to 'prove' that Hitler was alive and under US protection ).
So my opinion, derived from the reading of numerous books, is that the facts are settled.
Where WWII is concerned, the sad fact is that from now on, books are pretty much all we're going to get. I don't subscribe to the post-modernist view that 'history doesn't exist'. There comes a point when we have to use our own judgement of the professionalism and motives of the historians who write the books.
( BTW :
Who are the historians who make these 'History Channel' programmes ?
I'm just wondering, as I don't watch them....)