Most enemies in nonlinear RPGs.
Especially ones by Bioware and Bethesda. You'll be wandering around, tooled up to the tits with the largest collection of military hardware in the hemisphere, or more magical bling than an entire fantasy rap crew, and they'll poll up, make some pathetic threat, and then explode into a cloud of vapour as soon as you snap your fingers.
Really, people, write in some code for enemies to realise when you are harder than them and change their behaviour accordingly.