As an engineer, I like traps that make sense. The needle in a chest is fine, but I'd rather through all the thieves into a pool of acid and merely hurt them. Although I disliked their implementations, the encounter-traps that appeared in late 3.5 had the right idea. By the same token, a trap must have a way that people who live in the dungeon must be able to bypass easily (even if the answer is "they use the secret entrance").
However, I am not a big fan of puzzles in DnD. I do not write too many of them in my adventures.