Post what you think are the best sounds in any game you have played, be it voice acting, music, sound effects or whatever.

For me, it's gotta be the little 'beep' when you get stuck with a plasma grenade in Halo 3; extremely satisfying.

TF2 wins....forever.

Agreed.

I have to say the tau in dark crusade (err RTS). They scream about everything. I don't mean like a manly roar, more like they are all dying horrible, painful deaths. They will get shot from some weak guy and scream "ARMAGEDON!".

...(akward pause)

what else...
That thunk you here from the crossbow in half life 2.
The science facility guy from starcraft. It = gay robot.
Just to shorten the list, any sound that comes from Valve, kicks ass.
To prove this point, here is a song that is nothing but TF 2 scout sounds.
And it KICKS, ASS

gosh darnit...
heres the link.http://www.youtube.com/watch?v=6P-MKyb_h3I

more coming soon, it's beddy-bye time.

The chaos quotes are great. Particularly the cultists.

"Aaah, my spleen!"
"Crush, kill, haa haa, destroy!"
"Grant us the gift of the chaos gods, great one!" 
"DO YOU HEAR THE VOICES TOO?!"
"I feel the warp overtaking me... it is a good pain!"
"Sanity is for the weak!"
"It is as though a thousand mouths cry out in pain."
"Enemies! We need enemies!"
"Maim, kill, burn! MAIM, KILL, BURN!"
"Rend them in half!"
"I feel the maw of despair swallowing me!"
I am not your bootlick!"
"Blood, blood, blood, blood!"
"I drink their blood from their hearts!"
"Split them open!"
"Uuuaaarrarraaargh!"
"Kill! KILL!"
"For the slaughter!"
"Why aren't we killing yet!?"
"I will shatter their souls!"

And my personal favorite:

"Hwee haf captoored eet foar KAYOSS!"

F-Zero, anyone who plays it for extended periods will end up humming along to the tunes, that's gotta mean they're good.

Man, I gotta agree on this one. I still tend to launch up F-Zero X from VC on my wii just to listen to the tunes.

The screaming when you noob-chainsaw someone in GoW2 :')
`Specially the locust (which sound almost completely alike)

Super smash bros brawl:
Samus' cannon-laser beam.

Also MW2 semtex grenade beep

yeah TF2 sound pwns =D ' This is baaaad' =D
but i'd say Fable. epic sound you know. Voices and musec are just perfect.

in the games ive played, i like bioshock series' voice acting and BFBC2's detailed sound FX
also the headshot PINNNGGGG in a few first person shooters, like when you hit their helmet