I think there's a bimodal distribution on this thread - one is actual worst-ever cigars, and the other is the serious disappointments masquerading as premium cigars. I've had plenty of the latter, but for the former, I would have to say it's a bundle I bought at a little shop in rural Honduras in the 90s. It was something like the equivalent of a few bucks for a bundle of 16 or 20. My tastes were not at all refined at the time, but this one tasted like I was smoking mud. Stuck it out for about half of one, got a splitting headache, and pitched the whole lot of them.

With cigars, you don't always get what you pay for, but you never get what you don't pay for!