The only classic Onion article I've never been able to find again was "Alternate Reality James Hetfield Named Taco Bell Employee of Month," complete with a fantastically done (as always) photoshop job. I only wish it was in the archives.
That having been said, this one is a classic; my office door has the "Fifth Grade Peers Reject Science Report" article from around a year or so back.
EDIT - AWESOME!
Sorry for the OT, but I haven't seen this in years, and I was beginning to doubt that it ever existed.
"I tell you, when a homosexual is sucking your cock, a lot of strange thoughts go through your head: How the hell did this happen? Where did this fairy ever get the idea that I was gay? And where did he get those fantastic boots?"