Towards Utopia (Nova Flare) from Stellaris, but I will say one of my favorite things in a video game is when suddenly a character sings a musical number, like The Great Mighty Poo from Conkers Bad Fur Day or Cosmic I from Psychonauts 2

Stoic Porridge (Grit Gate) - Caves of Qud OST

https://www.youtube.com/watch?v=ZLXwXzYheUg

Solace.

N20

I had a soft spot for Icewind Dale’s soundtrack by Jeremy Soule.

I'm just gonna say Rainbow Cliffs from the Ty the Tasmanian Tiger OST, just because it has been my ringtone for a few years now and I still can't get enough of it.

Runner up is probably The Reverse Will from the Silent Hill 2 OST (original, not remake)

Razorback - motorstorm Pacific rift

I don't know why my brain refuses to let it go, but Graeme Norgate's Astrolander from Timesplitters 2 is short and very sweet.

Also theres the opening theme from Escape from the Planet of the Robot Monsters.

Oh actually also the Italy round of Road Rash 3. I once worked in an Italian restaurant and would whistle this without knowing it was taken from some famous Italian opera, and the owner asked me how I knew the music, and I didn't have the heart to tell him.

Ordinary from NFS:Hot Pursuit 2