Since 3e came out, I've run the following published adventures:
Basic/Expert D&D
B1: In Search of the Unknown
B2: The Keep on the Borderlands
B6: The Veiled Society
B9: Castle Caldwell and Beyond
X1: The Isle of Dread
Advanced Dungeons & Dragons
I3: Pharoah
I4: Oasis of the White Palm
I5: Lost Tomb of Martek
A1: Slave Pits of the Undercity
EX1: Dungeonland
EX2: The Land Beyond the Magic Mirror
S2: White Plume Mountain
U1: The Sinister Secret of Saltmarsh
U2: Danger at Dunwater
U3: The Final Enemy
AD&D 2nd Edition
WGA4: Vecna Lives!
RA1: Feast of Goblyns
D&D 3e
The Sunless Citadel
The Forge of Fury
The Speaker in Dreams
Deep Horizon
Dungeon Magazine adventures
Ashtar's Temple (#81)
Iriandel (#83)
Depths of Rage (#83)
Raiders of Galath Roost (#87)
The Seventh Arm (#88)
The Elfwhisper (#90)
Vanity (#93)
The Buzz in the Bridge (#110)
Torrents of Dread (#114)
Comments on old-edition modules
I love them.

Keep on the Borderlands provided a wonderful introduction for some new players to D&D. I've fond memories of two of the PCs hiding up a tree from the enraged minotaur...
Normally, the suggested levels aren't quite accurate, mainly because the older modules assume more players than are available, and because a few monsters (giants and dragons especially) have become more powerful with the newer editions.
I've noticed that the older modules can have a wide variety of play styles. Whilst Gygax's modules tend towards treasure acquisition and monster slaying, you also have intrigue (Veiled Society), horror (Feast of Goblyns), exploration (Isle of Dread) and epic quest (Desert of Desolation) styles available.
Adding my own adventures to season the mix, it's provided me with four years of great adventuring.
Cheers!