Auto-saves to the exclusion of manual ones...
I'm a save whore and love it...

Inventory limits in a dungeon crawler/loot-heavy game...
WTF, Why....WHY!? If I wanted to spend 80% of the game managing my inventory, I'd simply get a job at a warehouse! Plus, I'd get paid for my work...

Stingy economy in a dungeon crawler/loot heavy game...
So not only am I stuck micro-managing my inventory, I can't even sell half of it to pay for the psychotic 5:95 Selling/price gouge ratio so I can keep myself stocked up on fuckin' stamina/health poitions!? (Lookin' at you Inquisitor, you gorgeously-crafted-epic-storied game...You lovely bastard!...)

Obsessive/compulsive gambler RNG abuse...
I don't like to gamble, I don't even play the lottery, reasonable RNG should enhance gameplay, not replace it!...

Fuck you, Xcom 2, I'll have none of it from you...

QTE...In an RPG...Fuck no...Not for me...
'Nuff Said, wish it dead...

Developers adding/nerfing when people are in the middle of playing the game...
Looking at you CDPR/Techland/IndieDevs...Still love ya, much more than triple A though...

Carry Limits. And please don't even start the "realism" bullshit. Sleeping for an actual 8 hours is just as boring as going back and forth carrying loot yet the sleeping is "simulated" so why not the back and forth? Just get rid of the carry weight limits and be done with it. If I find 100 20 pound gold bars out adventuring, just simulate the 100 back and forth trips from town to the loot the same you simulate the 8 hours of sleeping and be done with it. Almost all RPG's would be so much better (and quicker) if they would get rid of the completely unnecessary back and forth loot trips.

Also, too, it always amuses me when someone plays the "realism" card to carrying limits in a world with fire breathing dragons and orcs and ogres and wizards.... please. just. stop. it.

Crafting
"RPG elements"
GPS/"quest arrows"

I assume most people prefer this, fast travel.

I know fast travel was a feature in DaggerFall, then they took it away in Morrowind. But Morrowind have fast travel in game too, by boat, striders and magic, I like how it's integrated and a part of the gameworld.

But I guess it makes sense to have fast travel for later Elder Scrolls games since their gameworlds are practically empty.

1. Switching characters (witcher 3 for example). Or gameplay style (you like stealth and come throught half game polishing abilites? Get the small room with a tank that will forcibly detect you by gamemechanics and suck.
Want play as infantry - now get that heli or fighter and kill that fly on 5 sec!

2. Small margins.
Can't play Ori since it need to make exact jump pattern with no single errors or halfsec delay. Change it by difficult levels is very forbidden by devs religions it looks like.

3. Grind (in all incarnations).
We need to report about very big game but kinda lazy to make content or story - lets force gamer to do same thing over and over for xp or loot. walk same map 100times. one (stupid) way to do thing (including "can explode a planet - can't smash a locked crate or wood door")

4. "You the chosen one, lets we all will kiss your ass whatever you go or do".
Disgusting

5. Timers.

6. "la resistance". All that gamedevs / movie makers obsession with "2person (preferably teens or adults with an IQ of 5years-old) fighting against THE SYSTEM!!!" heavily crying about medical atension.

7. "Realism".
When you laying on the ground and can't place a shot on target (not just happend but by game mechanic) from AK-74 (singe fire mode) on 50m it's realism.
When you get shot from running enemy with a handgun on 100m trought a bush - it's realism.
You got hit - you dead. Enemy got hit - it's nothing special.

Huds

but,

I love regenerating health (which a lot of people seem to dislike). It keeps me in the action and you don't need to show health on the hud any more.

Most of the time it does exactly the opposite. Regenerating health promotes gameplay revolving around constantly breaking up action to take cover so you can regenerate whereas healthkits or many hybrid systems which are popular nowadays promote recklessly jumping into the action and improvising.

Oh yeah, when I see traditionally jRPG or anime-ish art style I avoid the game like a plague - even if people praise widely praise it. Can't stand the art style.

Everything time based. I like to take my own time, and look around a bit, thank you very much. Don't stress me, I play to relax.

Legend of Grimrock 1 is horrible with all those time based puzzles, my fingers are just not fast enough.

Retention rate: how many players actually got around to this content. This is typically a disheartening figure for a level designer. I like achievements since I like statistics; I find global achievements to be more interesting than personal ones.

Stealth. STEALTH.

Specially in non-stealth games.

Agreed. As I mentioned earlier, this turned me off from the Zelda series.

Glad I'm not alone in that then.

Has anyone ever actually said they like QTEs? I thought it was only hopelessly out of touch devs who think that QTEs are a thing which gamers want?

They show up in so damned many games, that I just assumed there must be a fairly large segment of gamers that actually likes them.

Any boss that won't stay down.

I should never have to kill a boss more than twice in one battle (I'll grudgingly accept one resurrection/form change), or encounter him/her/it in a boss battle more than twice in one game.

Heh, JRPGs do that a lot: "You have just beaten me severely to near-death with heavy weapons and powerful spells. I am now going to show surprise mixed with respect and flee the scene with undiminished agility only to reappear at a latter time, utilising *all* of my powers this time. 'Cause I was now holding back, y'know, just to test you."