Patient Gamers

Borderlands 3, if you somehow missed it, for under £5 is just a good value.

I got myself and can recommend:
Returnal (29.99€) (Rogue-like shooter),
Wisper (6.99€) (Open world exploration) and Crossroads OS (3.74€) (Puzzle game).
I can further recommend:

Studio System (8.84€) (Horror),
With My Past (6.59€) (Puzzle),
Signalis (13.99€) (Horror).

I just bought Suicide Squad (I know, I know, but it was on sale and I want to experience it at least a little); Pine; and Sniper Elite 2R, 3 and 4.

I'm very excited to get into the Sniper Elite games. I played 5 back when I had Game Pass, but never finished. I figured the others might be just as good.

Caves of Qud has a small discount. I’ve been playing it a lot lately on the Steam Deck.

Talos Principle is $5

Talos Principle 2 is $15

Highly recommend both games!

I picked up civilization VI (for my PC), hades and outer wilds for my deck.

Celeste is 75% off and is a near-masterpiece of a game.

Portal 1 and Portal 2 are on sale again of course on the chance you haven't yet hit these absolutely classic legendary games.

Persona 4 Golden is 40% off and is awesome, and Persona 5 Royal is 60% and is even more awesome.

Metal: Hellsinger is 70% off and while it isn't a GOTY type game, it's a hell of a lot of fun if you're a contemporary metal music fan.

but my biggest recommendation is probably gonna be

Recettear: An Item Shop's Tale at 80% for only $3.99 (US) which is an completely underrated hidden gem of a game and a huge recommendation for anyone who likes quirky cozy-hybrid games or who, like me, spent way too long on the shopkeeper segments in RPGs like Torneko Taloon's chapter in DQIV.

edit: why in the world would anyone ever downvote a personal recommendation comment? Weird behavior, fam

Here’s what I picked up during the Steam Spring Sale:

DOOM - $1.99 (90% off)
Stray - $18.99 (40% off)
Undertale - $0.99 (90% off)
Celeste - $4.99 (75% off)
Star Wars Jedi: Fallen Order - $4.99 (90% off)
Red Dead Redemption 2 - $14.99 (75% off)
NieR: Automata - $15.99 (60% off)
Hades - $9.99 (60% off)
Devil May Cry 5 - $19.79 (67% off)

The Mafia Trilogy is $15 for the whole shebang, or $7.50 for any one of the individual games. I grabbed Mafia 3.

Mass Effect legendary edition (all 3 games + all DLCs) is on for 6 Euro.

That's a great deal IMO

Noita is currently 60% off and is hands down the best game I have ever played (kind of). It is ridiculously brutal and you will die very often but you have the potential to get ludicrously powerful as well. The game will cheese you so don't be afraid to cheese it back. In has so much content that beating the final boss for the first time is considered beating the tutorial.

Also if the some aspects are too bullshit for you there is a variety of mods to fix these, and there is absolutely no shame in using them.