I am expecting a lot of Disco Elysium, here...and nothing wrong with that!
A video gaming student organization I was once part of actually had a vote on their favorite sayings. The winner was the evergreen "Perhaps the same said could be said of all religions..." from Castlevania: Symphony of the Night! https://www.youtube.com/watch?v=OMTizJemHO8
My personal favorite? It's hard to say...but hey, that's what the scientist in Half-Life can comment, word to word! So maybe I'll put forward, said by the aforementioned: "My god, what are doing!?"
"Giving up already? Come on, Sora. I thought you were stronger than that"
Kingdom Hearts
"Hey motherfucker, the code of the streets Is i don't snitch, I don't care if it kills you, me or my brother, street cat call no cops" , CJ
GTA San Andreas
"We've lost the battle. Lord Vader will not be pleased."
OG Star Wars Battlefront
"I'm happy to see a familiar face... But I'd be happy to see a lot more than one".
-Ethan Cole from Area 51 (2005)
"My Life for Aiur" - StarCraft
"Truth Is, The Game Was Rigged From The Start.", Benny
Fallout New Vegas
"Jango Fett:
I'm taking Fust with me.
Zam Wessell:
Over my dead body.
Jango Fett:
If you insist..."
Star Wars Bounty Hunter (2002)
"Wahoo!" (When boosting) , Crash Bandicoot
CTR, Crash team racing
"A surveillance camera?!", Snake
Metal Gear Solid 1
" Prof Oak : That's right! I remember now! His name is BLUE! RED! Your very own POKEMON legend is about to unfold! A world of dreams and adventures with POKEMON awaits! Let's go!"
-Pokemon Yellow
"Listen To My Story. This May Be Our Last Chance.", Tidus
Final Fantasy X
(Not a quote but a classic gag)
"Jagex blocks your password if you type it in look: ******"
-OG RuneScape