World's spiciest chemical (resiniferatoxin)

Extracted straight from the African resin spurge, and tasted by yours truly: https://www.youtube.com/watch?v=XPe2bssalOY

World's stinkiest chemical (thioacetone)

Didn't "build it" per se, but I did synthesize it, and it REEKED to high heaven! https://www.youtube.com/watch?v=E_wboFJZBTU

Extreme Slayer Exciter

An easy-to-build, 120V-powered MOSFET Slayer Exciter (a form of solid-state Tesla coil) capable of producing 5" long bolts of lightning: https://www.youtube.com/watch?v=Q0lkg9lxz3s

• The 2017 Hackaday Prize

• Hackaday Prize 2019

• The 2018 Hackaday Prize

• 2021 Hackaday Prize