The Kindaichi Case Files/Awesome

Even if you don't include all the the brain-fryingly-awesome deductions, The Kindaichi Case Files has a bunch of moments where you just need to stop and stare.

"Culprit: No! I didn't do anything! I'm innocent!! Kindaichi: *Death Glare* Look me in the eye! If you still dare say that you're innocent, then look at this!! *reveals the hidden skeleton of previous victim* Well, ? Say that you're innocent in front of one of your victims!! SAY IT!"
 * In the manga volume 'Smoke and Mirrors' (also known as the seven school mysteries) Kindaichi himself has a goose-bump-inducing conversation with the killer at the end of his Investigation of Revenge: