One thing I never cared for, regarding combat in Fallout games, is enemies bum rushing you while your only defense is to run backwards while hip firing if you're not using V.A.T.S. Having some type of riot shield to use, if dual wielding is available, would be nice.
Like if you're using melee or any one handed weapon, being able to block or reduce damage from melee attacks (especially from ghouls or insects) or at least knock back enemies, similar to Skyrim.