Firefox for Android. "Refresh" and "Stop loading" buttons aren't on the toolbar, they're under additional submenu, as well as the "Forward" and "Back" buttons, so the most common browser actions are made cumbersome. To tune an extension like NoScript or uMatrix, you need to navigate a ton of menus and submenus, and then the settings are on a separate screen, not in a popup like in the desktop version. The tab bar got removed in one of the major updates one or two years ago, so now to switch tab or to open a new tab you need to navigate to a separate screen. It's like the devs want you to suffer when using it.

Amazing that this abominable thing shares code with the desktop version, which is quite usable (not to mention it allows very good introspection in devtools with a single F12 key press).

Pardon?

Probably The Witcher. I find the esthetics less bothersome than the fact that so much of the screen is constantly obscured by extraneous junk. I imagine it's somewhat less of an issue in the era of widescreen monitors, but it was very frustrating at the time.
Out in the world
Skill tree
Inventory

Fez is notorious for its [url=https://en.wikipedia.org/wiki/Fez_(video_game)#Design]obtuse metapuzzles[/url]. I'm sure there's no part of it that's meant to be helpful or gently nudge the player towards a solution.

Grimoire: Heralds of the Winged Exemplar came out in 2017 and took 20 years to make. There was quite a bit of fuss on the forum because it was initially rejected by GOG. I hope fans got the game they were hoping for.

Playstation 3
The UI was the be worst experience in my life, especially when applying new patch: please wait - loading a new data - please wait - applying patch, why can't they have just 1 please wait screen?

PSN
PSN store UI is another pain, the search function doesn't work the way I expected, finding all purchased games was not possible, as a workaround I had to find all downloaded media including patches, that was a mess. They fixed it in later versions for PS4 I think but I lost my interest in console gaming, so I don't care anymore.

Resident Evil: Village
I started the game and noticed that my mouse sensitivity could use some tweaking. The problem is that UI was created by none other but aliens from outer space and I had to spend 5 minutes finding the proper settings and accidentally changing mouse sensitivity in menu instead, that was SO useful, especially with separation for vertical and horizontal.

Ultima 7's UI is pretty bad.

For example:
* Movement is done by moving the cursor away from the character until an arrow appears, then clicking the arrow. I'm pretty sure you can't just use the keyboard.
* The inventory system is horrible. To find an item you need, you may need to move other items and do some pixel hunting, if I remember correctly.
* That factor is made worse by the way the hunger system forces you to interact with it. To feed a party member, you need to go into the inventory, find a food item, then use that food item on the character. Oh, and you can't just skip this; characters will eventually starve if not fed. (Earlier Ultima games handled it better; just buy enough food and you don't need to do anything else to prevent starvation. In fact, Ultima 6 made it so that food is only consumed on rest, which is how it should be (or have food give optional bonuses).)
* Don't have a mouse? Then you can't play this game. (That's actually an issue with way too many games, but the previous game, Ultima 6, can be played without one, even though the game does have mouse support.)

I'd rather have the interface of the original Dragon Quest 1, where you have to choose a direction whenever you use the Talk command, and have to use the Stairs command to climb stairs, over this. (Well, maybe not the password system for saving. Remember those?)

I've always thought that inventory screens in RPGs could be better designed. Most of the time there's no need for all the visual clutter, the many items on display which overwhelm the player and force him/her to make unnecessary choices, the right click submenus, lack of categorisation, etc.

Strategy games such as Crusader Kings II or the Total War series also tend to do a poor job at displaying information in a usable and legible way (the latter is also notorious for lacking personality and looking bland, Three Kingdoms notwithstanding), thus increasing the learning curve required to enjoy them.

And regarding operating systems, I'd say that Windows's UI is by far the worst because of its lack of cohesion and unnecessary complexity (though this could improve once W11 leaves early access). And then most Linux desktop environments except Gnome, because even though Gnome has its flaws, it's still better than the rest.

Yes, I remember it being featured on an episode of Good Design/Bad Design. While the author noted that the game was great, it was more in spite of things, rather than because of. Not just metapuzzles, but the game's creator alleged that as of (some) recent point, there were still undiscovered secrets. And it both looks and doesn't look the part of a game which took 20 years.

Ah, good ole recursive information boxes. I recall this being an issue on the Vita, too. Yep, I remember this. On the Vita it was a submenu crammed into the right corner. People may have liked the Vita, but the menu wasn't why. Welcome to Japanese Console to PC Ports. If you get a good one, bless the stars themselves.

Answering UX more than just UI.

Every Ultima game I tried. Admittedly not many, but a couple.

Pretty much every "Grand Strategy" game, but especially the Paradox / EU ones that I tried. I swear half of why these games are complex and uninviting is because their UX is so convoluted. I tried Star Dynasties and OH BOY as it unapproachable.

Alone in the Dark. I heard it was awesome, couldn't get over the controls. There was also a "point and click adventure" game that was highly-rated but when I tried to play it surprised me with this mess of tank controls. I forget which game that was.

I love Grim Dawn, but the devotion screen definitely went far for form over function. It's much improved since they added search though.

Also, every game with intentionally obtuse, hidden, or lying mechanics... "Soulslikes", games that lie about their spells' functions, or have flavor text on an item that indicates it does more than it actually does.

As for being just plain eye-burningly ugly (with some of the worst fontwork ever), I couldn't stand watching my husband play Loop Hero. The game itself is probably one I'd enjoy to some degree, but it's about the ugliest thing ever. It's like they wanted to make a game that was CGA-designed-but-late-upgraded-to-EGA, but the color palette was created by the Quake artists, where somehow even the blue looks brown. PS3? I didn't find the "cross bar" UI that bad, especially compared to late Xbox 360 UIs (earlier ones were better) and XBone's masterpiece of shit. But agreed on PSN's store UI being awful. I don't have any idea how/if the Xbox one changed, but Xbox 360's was tight. Fortunately, I don't really use console digital stores.

EDIT: Honorable UX disgustingness mention for "any game that relies on controller vibration/rumble for a feature". I turn that [physically painful] shit off. A couple of Zeldas are guilty of this for their in-game treasure-finders. Original release of Ghost of Tsushima did as well, until they added light and sound in as part of an accessibility features patch. I know there are others.

I know! Imagine bookmarks actually being accessible enough to use to save time instead of a dozen taps to open one.

The interface of Grimoire could be defined as terrible for a modern game, indeed. But considering that the game was 20 years in the making and that is a game focused for people who knows what is it, this is, a wizardry 7 interface like, well, then it is not so bad. It could be considerd as a familiar land. Pure niche.

Unecesarilly complex interface but it was the intention, I guess. Also, the game is a monster, If you need to learn an UI to enjoy this game, do it. It is worth the time if you are interested in this "microsubgenre"

Kingdoms of Amalur and the remaster both have a horrendous menu system that is completely cumbersome.

Also, Skyrim's UI is terrible.

That's what you get with decades worth of spaghetti code while trying not to break backwards compatibility.

Most of the RPGs I've played use simple text lists. Tome4 also has this problem, especially when comparing upgrades of items. Feels like you'd need a graph to show what swapping each item would do. I really don't gel with Gnome, because it represents the antithesis of user control. Plus the huge title bars and need to augment to change standard settings. In fact, I prefer things like i3/Sway or NsCDE.