The first adventure I ran was
The Labrynth of Madness, but it was just for a one off, for only one session. Our groups regular DM either wasn't available or wanted a break for a week (don't remember which - it was 15 years ago). So, the group got to mess around with making some high level characters and try a really dangerous adventure. It didn't become a campaign since we had intended it to be just one game session.
On a sidenote, I put the adventure in FR and had Elminster ask the characters to seek something in the
Labrynth (I don't remember the exact plot hook I used). One of the players decided they wanted to taunt Elminster (as players are wont to do) while they were camping. Instead of using some uber powerful attack spell to dispense with the annoying PC, I remembered those articles in
Dragon where Elminster and some other powerful mages would meet at Ed Greenwoods house. So, since I surmised Elminster is familiar with modern day earth, he teleported the annoying PC. The PC found himself held by a bar in a small cart (like a mining cart - or a roller coaster
), while it was being pulled up a really tall hill on tracks. After clicking to the top, and the PC unable to get out, the cart tops the hill and starts screaming downhill at a speed the PC has never experienced. Just before it reaches the bottom, the PC is brought back to where he was beside the fire, unharmed except for hair and clothes in dissaray. Everybody got a kick out of it (including the annoying PC).
After that, I didn't DM again until a couple of years later. I ran a
Dungeon adventure called
The Object of Desire, from issue 50. It provided the party with a cool base of operations after completing the adventure, and did become a campaign. The adventure worked so well, I've pulled it out, and blown the dust off it for the current group I'm DM'ing for.