Well, in Dungeon #116 (November, 2004) appeared the famous "30 Greatest D&D Adventures of All Time" - voted by the fans, IF I´m correct:
The Top 5
1) Queen of the Spiders, 1986 (G1-3, D1-3, Q1)
2) Ravenloft, 1983 (I6)
3) Tomb of Horrors, 1978 (S1)
4) The Temple of Elemental Evil, 1985 (T1-4)
5) Expedition to the Barrier Peaks, 1980 (S3)
Obviously, it only goes up to 2004 -so, no "Red Hand of Doom" here - by the by, the only 3rd edition adventures in the list were:
8) Return to the Temple of Elemental Evil, 2001
12) The Forge of Fury, 2000
24) City of the Spider Queen
...And the only "non-TSR/WotC" was
21) Dark Tower, 1980 (from Judge´s Guild)
The 30th was:
30) The Ghost Tower of Inverness, 1980 (C2)
And some tidbits:
7) The Keep on the Borderlands, 1979 (B2)
9) White Plume Mountain, 1979 (S2)
15) Castle Amber, 1981 (X2)
17) Ruins of Undermountain, 1991 - the FR mega-adventure
20) Scourge of the Slave Lords, 1986 (A 1-4)
22) The Lost Caverns of Tsojcanth, 1982 (S4)
25) Dragons of Despair, 1984 (DL1) - the first of the Dragonlance adventures
It´s interesting to notice that, in 1st edition, D&D was defined by its´s ADVENTURES, in 2nd and 3rd editions, by it´s SETTINGS, and, up to this point, 4th edition has been defined by it´s RULES.
DM from Brazil / Daniel Lira de Oliveira