I pretty much missed Dungeon magazine as when it came out as I was mostly playing non TSR games and/or working on my car instead of gaming.
I returned to it later and I was generally astonished firstly by how few dungeon adventures there were in Dungeon (since by that time TSR felt that there passe, I guess) and how awful the adventures were, mostly churned out by the same handful of terrible authors.
(What's especially annoying is in later issues is how they spread out each adventure between the front and back of the magazine.)
Still for all it's faults, Dungeon still is a huge source of adventures and encounters. If you can find them.
UnknownCorrespondant has compiled a very comprehensive index of TSR era adventures sorted by level over at RPG.Net including a brief synopsis of each adventure.