Hmm, I might have to break this down into sections.
Number one on my hit list... Escort missions; I absolutely hate these things. If done well they are unobtrusive at best, game breaking frustrating at worst. I can't think of even one example where escorting an NPC has ever been enjoyable (though I do recall some hilarious banter from time to time).
Number two with a bullet... Side missions for the sake of side missions; First let me say, I don't dislike the idea of side missions. In fact, I rather enjoy them when done right. What irks me to no end however is how some games rely on them to bloat the play time of a game. I am notorious for wanting to complete every mission on my first play-through (almost OCD about it), so when games just artificially reuse the same side mission formula repeatedly I get terribly bored with the game. I can only go kill 5 guards for their keys so many times before I feel as though I'm playing some terrible form of quarter eating arcade machine.
And on the subject of keys...
Number three in the circus of horrible... Keys sticking in my inventory with no purpose; My hatred of keys in games stems back from the early days of FPS games, but this isn't what I'm talking about. I can't stand it when games have you collect keys to get through doors one time (it isn't like these doors relock themselves, or even the doors close) and then the key stays with you the rest of your life. RPGs are the primary offender here. Games like the new fallouts or oblivion where you have an inventory, and its usually half full of keys to random doors you will never see again in your life. My first inclination would be to throw the keys away or delete them... no such luck. Not only are they vaguely unimportant keys, they are also cursed keys. They will remain with you long after you are gone.
Number four on my list of no no's... Intentionally bloated affix lists; I do enjoy my RPGs, especially the ones that rely on random drops (think diablo). What I do not enjoy are games that rely on random drops adding five-hundred potential affixes that are absolutely meaningless or in such small increments as to become pointless. Diablo 3 was ruined for me because of this. I don't mind it if you want some quirky affixes added into the game, but don't make them eat up the slots that could be potentially used for something useful. Why do I want -1% fall speed on my boots of shiny awesomeness of ass kickery when it could be +10% to liquify enemy brains? Either make a secondary slot for the goofy affixes, or don't include them.
Number five thing that chaffs my willy; Multiple crouch levels; Stalker is the primary offender here, but I've seen at least one other game do it. This is when you press your crouch button and your character stoops over just a smidge. You aren't really able to get under anything or use it to duck a blow... unless you press a second button at the same time, this actually makes your character crouch (note I am not talking about crouching and prone, but two levels of crouch). I am already trying to move forward while jumping into a window, do I really need to press half the keyboard to do this?
Number six pick up sticks... Games with questionable controller support; Have you ever played a PC game and you just didn't feel like sitting up, so you lean back and grab your trusty death stick... only to find that the controller support, only actually supports half the commands that the game uses. Sure you can run around, jump, shoot, crouch, and play with your johnson, but you can't heal, talk, or cast your trusty spell of furby summoning without sitting up and using the keyboard. These games usually only utilize half of your controller buttons as well. My usual reaction is to go into options and try to customize the controller lay out, this is when I find out...
Number seven of things that won't get game devs into heaven... I can't modify my button lay out; Why, in this day in age of games, can we not modify our buttons in half the AAA titles? I have been able to modify my control options since the days of nintendo and dos. I know the technology is out there. Hell we have spray on batteries for the love of (insert deity of your choosing). I won't elaborate too much on this, as I am sure everyone knows what I am talking about.
Number eight on this too long list... Games with tutorials that go on far to long; When you make a game a choice is made to include a tutorial or not. This choice is usually made based on how complicated the game is. I have no particular issues with complicated games having tutorials, where I take offense is when they go out of their way to make it so simple that a retarded spider monkey on bath salts could not only play the game, but also write a dissertation on the subject of the control scheme. All the tutorial should do is tell you how to control the game, and introduce you to gameplay elements that are new to the genre. There is no reason to make the tutorial longer than the first half of the game.
Number nine won't you be mine... Tutorials (oh yes, I'm not done yet) that don't explain anything relevant; So the decision was made to include a tutorial, and they read the preceding complaint, so they decide to keep the tutorial short and to the point. What they do wrong is to make it so short and to the point that the tutorial only goes as far as to say, use this button to move forward, use this button to move left, use this button to shoot, figure out the rest of the game on your own. If the game is standard fare of it's genre, fine. You don't need an overly elaborate tutorial (though if its going to be that pointless, don't even include it), my grievance is when that is the tutorial you receive, but the game is set up like a quantum physics experiment.
Number ten thing of questionable intent... Forced walking sections; Okay you've built up a high speed tempo in this spunkgurgleweewee game that has my heart racing and I'm running forward with the speed of a cheetah and the ferocity of an angry penguin and hit a brick wall of slow the fuck down. These sections are usually accompanied by some general/commander/captain in charge of my unit telling everyone what the plan is and why we are doing this, then they will set us loose with a waypoint on what we need to do, a journal entry on what we need to do, an objective screen on what we need to do, a radio with a guy screaming in our ear what we are supposed to be doing, a banner on the top of the screen telling us what we need to be doing, a golden trail showing the path to what we need to be doing, and an ancient stone tablet with cave writing that tells us what we need to be doing (and why we are an idiot for buying the game in the first place). The point is, slowing the pace of the game by forcing us to walk when our normal speed is that of someone on a scooter bike and our sprint is the speed of a light weight tank, will only serve in aggravating us as our game play has been interrupted.
I could continue with my list of grievances, but I think I will leave it here for the time being. Perhaps I will write a sequel later today, because we all know how much I like sequels.