Double barrel shotgun. I've never even bothered to fire it on the range, it's an instant sell,and serves no purpose. Unlike the sawn off which is perfect for breaching/blowing off locks, and good as a last resort one shot kill on most things at close range. Also pretty effective at taking down armored elites with three shells if you hit them in the junk.
Pistols, especially revolvers. Much like the real world, if you are having to use a sidearm you are in serious trouble and everything else must have gone to hell. Although I do keep one in the inventory simply so I can use the flashlight.
I'm not saying what else I don't use much. I half expect anything actually worthwhile using to get nerfed as a result with the next patch!![]()