There's truly only one choice

Fireball fireball fireball and oh fireball

Just Fireball.
I've been using ice storm a lot more. It has a wider radius, does almost as much damage, and imposes difficult terrain, which frequently knocks enemies prone, wasting their turn.

Uh…counterspell?

Best spell in the game.

Edit: also for clerics i’d pick spirit guardians over everything.

Playing a druid currently and I couldn't count the number of vile glares I've gotten from the DM as I utter "I cast Dispell Magic"...
- Spore Druid and Call Lightning is absolutely amazing. A level 3+ spell that you can cast infinite times without expending further spell slots? Oh hell yes, please!
I don't pick Counterspell because I don't want to piss off my DM.
- My current wizard character didn't take counterspell until the dm sent a wizard at us with it first. He had no one to blame but himself.
- They need to think more creatively. You're now focused on countering the enemy caster, and the party might be more distracted helping you to clear out the threat.
  
  This is the perfect opportunity to take advantage of, and put some nice pressure down.
Hypnotic Pattern. Damage is for chumps. Mass save or suck for me

This says a lot about spells in 5e.

Yes, there are many great choices, but one choice is usually greater than others.

Come to Pathfinder, where all the spells are kind of okay I guess.
please don't kill me
- Pathfinder 2 is even worse in that regard. You have a few kind of okay ones and then a bunch you’ll essentially never use. The price of Pf2s strife for “balance”.
- Hey now, you only need to pick twelve interdependent feats in order to make Counterspell useful!
- I think my next stop on the TTRPG tour will be Blades In The Dark. I borrowed the flashback mechanic for a 5e heist and it was pretty great.

Hypnotic Pattern, Haste, and Revivify are all great choices too

But

Fireball, Fireball, and (Fireball for Light clerics) Spirit Guardians is understandable

(Fireball for Light clerics)

"What kind of holy man packs Fireballs?!?"

"The awesome kind, that you're lucky to afford. Now stand clear."
Is hypnotic pattern actually good? I tried it, and it was mostly resisted every time I cast it, so I dumped it.
- Hypnotic pattern is good if you know what you're casting it against isn't immune or resistant to Charm.
  
  If it isn't resisted, it can be a combat-ending spell.

Is this some sort of DnD joke I'm too Pathfinder to understand?

It's some kind of leveled spell joke I'm too GURPS to understand. Am I to believe that magic only works at arbitrary discrete levels? Surely any competent mage can vary the intensity of their spells with the mana they invest, no?
- Energy can be measured in discrete quanta, there is no reason magic can't.
  
  To be fair though the fact that energy comes in packets does fuck me up
- Did you learn algebra before 7th grade?
No, this works in Pathfinder too. There is a very obvious meta and people follow it.
- Fair enough! What's the Pathfinder 3rd tier spell everybody chooses? :D

Tiny hut.

What about tiny fireball?
- Think A wall of force and a fireball can make a fireball hut?

Fear,Counterspell, Hypnotic Pattern, Fireball, Haste, and Revivify + Spirit Guardians (for the divine soul sorcerer) are just too good.

Spirit Shroud is also great for Martials.

Ashardalaon’s stride is really really fun in the right place as well. Unmitigated fire damage just for using your move speed? Not always worth the concentration slot, but by far one of the coolest 3rd level spells.

I’m a big fan of Plant Growth too actually. But that’s more Bard and Druid.

Feign death every time. Most OP spell in the game.

Clerics don't need to choose.