Day of the Tentacle is also one of the few point and clicks I've finished from beginning to end without consulting a walkthrough. This is actually one reason that I personally prefer it to COMI, the puzzles in DOTT generally are sensible/logical for the most part, especially by genre standards.
The absolute worst puzzle for me remains the infamous Broken Sword/Circle of Blood Irish goat scene:
I made it so close to finishing without a guide, but I never thought to Close the Door, and wasted hours trying to find the next thing before finally giving up.
The absolute worst puzzle for me remains the infamous Broken Sword/Circle of Blood Irish goat scene:
> https://en.wikipedia.org/wiki/The_Goat_Puzzle