From a gameplay perspective GTA has been mid for ages.

From the 360 Era — Too Human
The control scheme is bizarre at first (right stick is melee) but it works once you're used to it. It's Sci-Fi Norse mythology, I recall it having a pretty solid art style. I picked it up used from either Blockbuster or EB because I wanted to see just how bad it was, ended up enjoying it far more than I expected, I'll give it a "Yeah, it's ok", disc images are readily available if you want to emulate it, can find a physical copy cheap online too if that's your thing.

This is the game that ended up taking down its studio (Silicon Knights, they developed Eternal Darkness: Sanity's Requiem and Blood Omen: Legacy of Kain, they tried to sue Epic, who countersued and won, probably added to my initial interested tbh.

I think Halo Infinite qualifies, I played the multiplayer waaay back when it released so things may have drastically changed (haven't heard of it being the case);
it didn't / doesn't do anything that no other game does, nor did / does it do anything particularly well nor better than its competitors (including every Halo from Bungie).

I did watch a walkthrough of the campaign, and it doesn't look particularly engaging either.

Every Halloween, I play this Xbox 360 (I think it's also on PC now) game called Bullet Witch.

Basically a third-person shooter with postapocalyptic supernatural horror theme. You play as a witch who shoots zombies and weird creatures with a magic machine gun broom thing. Also you get spells. Some are bloody awesome.

This game is peak Xbox 360 to the core. The distinct memorable thing about it is that I can actually list good and bad things about it. Level design varies between meh and decent. Some of the particular setpieces are pretty awesome though. (You get to fight at an airport, and you get to do a boss fight at the top of the plane mid-flight!) Spells are fun. The mega-spells are hella fun. (Just call up lightning and watch stuff explode.) Shooting is kinda jank but it works. Jank is explained by lore. (Why is friendly fire not a thing? Well, you see, this is a magic machine gun broom thing, so bullets dodge the civilians and allies by ~*~magic~*~.) Enemy designs are nothing to write home about at first glance, but are actually kinda memorable. (You first meet up the zombies and hey, they're talking zombies. With military helmets and guns. Like, what? You don't see this every day.) There are some things that seem just not very well designed, like there's these gigantic enemies that serve as minibosses and they're a lot less scary when you note the AI is probably bugged and they often just decide to stand at place for a while and eat a lot of bullets.

I got this thing in the bargain bin. It's a zombie shooty game that's perfect for Halloween so that's what I use it for. That's all it does. That's all I could ask it for. And it's fine at it.

Square Enix games (FInal Fantasy, Neir Automata, Sleeping Dogs. Tomb Raiders)

They are all... good - certainly not bad games But nothing makes them... great

Dual nominations for Paper Mario: Sticker Star & Paper Mario: Color Splash. The only thing I really remember about them is that I played them and they left me without any feelings about them whatsoever.

The Halo series.

I like shooters, so I got the full bundle and I tried hard to like it.

None of the games gave me a lasting impression. The plot didn't stick with me, the enemies were weird, the guns felt weak and flimsy, the rooms kept repeating in some sections and it got very boring. There were some fun bits with the vehicles, etc., but overall the experience was... pretty much average.

I was expecting something like the Half-Life series, but this wasn't it.

2 that make fans go bananas.

Torchlight 2; Grim Dawn

Right in the middle of the middle part of the middle part of the middle pack.

Elex 1 and Elex 2

I said any Call of Duty from the past decade as answer to the original comment, and I still think that is a solid candidate. However, another game I played recently that qualifies I think is Sleeping Dogs. Perfectly cromulent 7/10 GTA clone but ultimately not pulling up any trees.

Team Fortress 2:

I'd say its gameplay is more "robust" than special. Like you can have any and every kind of fight in TF2 but none of it is more special than an FPS that specializes in any game mode.

Unreal 2, at launch, was the most absolutely 7/10 game I've ever played. Just a very generic singleplayer FPS, and not the sequel to Unreal that everyone was hoping for.

I say "at launch," though, because almost a year after the game's release, they added multiplayer, and that is still my favorite multiplayer game.

Just Cause 3

Movement was more annoying than Just Cause 2

Warhammer 40,000: Space Marine.

Godus.

I know lots of people hate it but taken in isolation it's okay. I found its aesthetics charming and its pace generally pretty chill. It wasn't good but it wasn't terrible. Low medium perhaps but I have comfortable memories of listening to an audiobook whilst playing it.

Neverwinter Nights

The multiplayer is supposedly incredible. But I remember being extremely whelmed by the main game.

But it's hard to remember the mid games. Because it is very likely that they didn't leave any lasting impression.

And especially if previous titles in a series or from a studio were great a mid game would feel disappointingly bad. Although compared to other games they might actually still be considered great.

avowed and ACS were actually less than mid