I'll name that beep in one.

[second only to The One]

"suicide!" from the halo announcer makes me laugh

the sound of a critical hit making contact in TF2 (or even just watching a teammate falling from a headshot)
any sound the pyro makes

the sound of someone hitting a bumper in smash bros. or smash bros brawl

 

[Weimdog]

HL2; The screams of a distant (or right in-your-face) super zombie.
Secret of Mana; The 'click' when you've held B long enough to charge 9 levels of punch glove attack... Good lord that combo never ends if you get it to hit.
CS 1.6; The 'gush' of an unarmored headshot.

 

[The Franco]

The beeping noise of the turrets in TF2 scare the piss out of me. Also the noise poison headcrabs make. /*shudders*/ ...god I hate that.

 

[Fire Daemon]

I think the sound of the Hammer of Dawn in gears of War.

Blink-bing-bing-bing-biiiing-KABLOOOOOOOOOOOOOOOOOOM!!!!!!

Or the Grenade tag noise.

 

[ElArabDeMagnifico]

I hear so many Half-Life sound effects in CGI movies, I saw Ratatouille and some old lady grabbed a shotgun, and when she reloaded it, I heard the reload sound (that weird "chick-kluhk" one) from Half-Life...

-

I love the TF2 Ubercharge, it's like a subtle "OH YEAH YOU ARE ALL GONNA DIE NOW! RUN AWAY!"

Which reminds me of when you get an "invincible star" on Super Smash...and that also reminds me of when someone gets a Hammer...

Oh, and the chainsaws in RE4 make me panic like, every time I hear them. Now that I think about, I think I know almost every sound effect in that game.

 

[iamnotincompliance]

Cliff Racer noises in Morrowind...

Gah! Much hatred for that one. Everytime time it comes up, I have to say something to the effect of "Fuck! Not again! Where the hell are these things coming from?!" Especially when there are several of them, and your sword wears out from use, plus there's the awkward hit detection, but now I'm rambling.

"Still Alive": Portal credits song

i'm possibly the most rabid portal fan in existence, but sitting next to someone playing this on repeat without headphones just defies imagination. To play this song in public you need a license, and even then only twice a day, at most.

that said, if used conservatively, its one of the most pleasing experiences to suddenly and unexpectedly hear this off your shuffle'd itunes.

True that. Although really, anything GLaDOS (or the turrets) say is pure gaming/comedy gold.

As for other sound effects (or quotes, where this thread seems to be going), I must say anything from the Worms series, at least 2D Worms (never tried 3D Worms, heard bad things). Quotes, sound effects, all genius.

 

[The_root_of_all_evil]

Gah, no quotes, we have thousands of those threads. Scorpion's count as it's just a vocal SFX rather than a quote.

 

[Xanadu84]

I second the Sonic air bubble. Made ME feel short of breath.

Also, the hissing sound of poison head crabs in HL2, because I hate those things, and for real terror, the Zombies moan in System Shock 2.

 

[thebobmaster_v1legacy]

I second the EQ ding, along with the "finish a quest" sound.

 

[Logan Westbrook]

The Soft ding of an unlocked achevment on 360. "Its been 2 heart beats and I never got my points, NOOOOOOOOOO- ..... oh Yay".

That's a great noise. I'm slightly worried though, as I sometimes hear it when I'm nowhere near my 360. I put it down to auditory hallucinations.

 

[The_root_of_all_evil]

The 'ching' of a gem dropping in Diablo 2. MMmmmm.

 

[GrimRox]

I love the sound the Pulse Rifle makes in Half Life 2. Makes me feel all warm and fuzzy inside, plus the sound of the distant gun battles in the same game. Conker's Bad Fur Day headshot noises where pretty gruesome. The Big Daddy voices in Bioshock are epic too! I can't narrow this one down to a single sound effect but playing the beach level at the start of Medal of Honour - Frontline (?) on PS2 with surround sound on, turned right up!

 

[The_root_of_all_evil]

Oh and the charging Gold Armour in Ghouls and Ghosts.

Vrrrrrrrrrrrrrrrrrrrrrrrrrrrp - KACHAM!

 

[losethegame101]

Delight:
The little "Pif/Paf" sounds the Half-Life 2 pistol makes.
The little "You got a new item" jingles from Metroid Prime and Zelda.

 

[Telferoo]

Cliff Racer noises in Morrowind...

i hated them with a passion.
and i like the metal gear Brwing! when you were spotted, makes me jump every time.

 

[L4Y Duke]

You just gotta love the "Tri-mask" music from the Crash Bandicoot games made by Naughty Dog.

 

[AngryMan]

The Ion Cannon sound from dystopia. Especially when I'm the guy firing the damn thing. That "B-ZHEEEEWWWMMM!!!!" sound is sweet as all hell.

conversely, there is no sound that makes me wary quite like the warning hiss-rattle of a black headcrab.

 

[Scott_Berg]

No idea why, but Kefka's laugh in Final Fantasy 3/6 has always been a favourite VG noise.

 

[Strafe Mcgee]

The muted "bmmmmph" explosion noise when a nuke hits an enemy silo in Defcon. Nothing better... Though at the same time, the "MISSILES LAUNCHED" alarm noise is terrifying.