Two that come to mind, the worse, a cheap, piece of c--- H&R or New England single shot 12 ga. weighing in at about 6 lbs and taking the 3.5" shells; muzzle-light to boot. Touched off a round thinking it would be a down 'n dirty turkey snuffer. Conditions were such that I was on my haunches, Indian style, and it promptly dumped me, blunt end down, into a pool of water.

The second a 458 Lott 500-grainer at top end, about 2400 fps off the bench--sitting; about a 9.5 lb rifle. Though finely made, my love affair with that rifle ended quite soon.