A position, rather than an opinion as it is often referred to, that the accepted wisdom
regarding the events of the holocaust is misguided, oversimplified or plain wrong.
Holocaust deniers range in their assertions anywhere from complete denial to more (pseudo)scientifically minded skepticism.
Complete denial is usually put forth by neo-Nazis and other racial supremacists claiming that a systematic annihilation of people by the Nazis during WWII never happened at all, but rather was completely fabricated as a part of a Jewish conspiracy to take over the world. At the other end of the spectrum there is the once-respected historian David Irving, who asserts variously that systematic murder did happen, but on a much smaller scale than is believed (thousands rather than millions) and that Hitler never knew of or condoned any of the actions leading up to it.
The established academic community tends to react very badly to claims such as these, and refuse to deal with their assertions in any well-organised manner. This of course lends the likes of Irving credence with the disgruntled and cause-hungry public that comprises much of the racial supremacy groups in the world, turning them into intellectual martyrs and reinforcing the belief in a Jewish conspiracy.
Why the whole holocaust denial thing is so centred on Jews I can't say. No one seems to get into enough of a lather over the systematic murder of Gypsies, homosexuals or the disabled to try and debunk its existence, a fact that rather serves to reinforce the impression that holocaust denial is a thing of racism rather than academic integrity. (On a side note, it's also a shame, because public opinion is not, in my opinion, well enough informed about the plight of these communities during WWII.)
My belief is that the holocaust deniers will survive the test of time, due to their effective debate techniques of hard-to-detect straw men and largely sentimental polemics, and that at some point in the future the story of WWII will be reviewed by keen young research students as a case of history being written by the winners. Because so much of the evidence was destroyed by the Nazi high command, and because the death camps themselves are being slowly revamped to look almost like pleasure grounds, there's no knowing how, ultimately, history will judge the holocaust.