In my opinion, the October 1979 issue of Heavy Metal was the best ever published. A 'theme' issue devoted to H. P. Lovecraft, the October issue featured memorable works from a number of contributors both veteran and new, including Moebius, Arthur Suydam, Serge Clerc, Alberto Breccia, and Jean-Michel Nicollet.
Perhaps as a reflection of the quality of this issue, back copies in good condition are among the most expensive on offer at eBay and amazon.com.
Throughout October I'll be celebrating Halloween by posting stories from this issue. I'll lead off with Serge Clerc's 'The Man From Black-hole'.