I got a few choice ones I've been savin up...
Explosives in games. You know em when you see em, those big, red things that explode violently when you so much as sneeze on them by accident. If these things are so volatile that they can be set off by (giving examples from DDO) being struck by a wooden fucking stick, being pierced by an arrow...OR BEING HIT BY A FUCKING MAGIC RAY OF COLD...why aren't they behind lock-and-key in a secure location where their exceptionally volatile contents don't run the chance of killing people by sheer happenstance? You'd think that places like Stormreach would have laws about that kinda shit...
Doors. I know, this is -extremely- nitpicky, but...say I'm a big, strapping hero who can easily deadlift a Volkswagen. Why, then, do I have to go through the convoluted process of going through a dungeon filled to the brim with monsters of all varieties, dodging traps that have killed dozens of would-be adventurers, and solving puzzles that would leave even the most astute wizards scratching their heads? Why can't I just break down the flimsy, wooden door with an axe? Hell, if I'm a mage, I should be able to blast the motherfucker open with a fireball or two. If its a metal door, whip out the acid. For fuck's sake, its a few plinths of wood held together with iron bars and studs, I should be able to break it open with a sledgehammer, if I have one. Or, alternatively, drag one of those explosive barrels over to it and flick a rock at it, blasting the bastard open.
And don't get me started on Load-Bearing Villains...