Most effective Elaborate Death Traps utilized by Big Bads?

[Schattenbach]

I'm curious about what seem to be the most effective elaborate death traps employed by the various varieties of big bad type villains in fiction? Are some especially deathly? Some especially crafty? Some so elaborate and unnecessarily complex that only the vast power of the villain (or the profound in-depth knowledge about the target) allowed the death trap to succeed? How do they compare they with each other in being good - well, deadly - death traps?