when cold fusion was announced. I still don't think it was meant as a hoax, though it may have been an observational anamoly that Pons and Fleishman never understood... I seem to remember that while nobody could duplicate thier results, there were 'oddities', though for the life of me I can't remember what they were. (I could be wrong - when nothing panned out I stopped paying attention to the 'scandal')
I hope this one goes further - fusion would solve a lot of problems, especially if it turned out to be relatively clean...