What are some of your favorite/most memorable sound effects and/or voice samples from a video game?

The first game that came to mind was Gauntlet on the NES.

The yellowish stun panels and green acid blobs made very distinctive noises. In fact, I've never heard anything like the acid blobs anywhere else.

Coins dropping in River City Ransom (NES) is one of my favorites. Nothing else comes to mind for that.

I thought that Conker's Bad Fur Day on N64 made excellent use of the N64's sound capabilities.

Unfortunately, nothing else immediately springs to mind . . .

I'm currently playing Resident Evil 4, and I think all the voice work is amazing, especially the enemies -

"Cerebros, Cerebros, Cerebros"
"Coquello, Coquello, Coquello" et all

My favorite is from the Sly Cooper series when Sly's sneaking around an enemy... the musical footsteps are awesome.

Least favorite? Navi from Zelda: OOT. "HEY! LISTEN! HEY! HEY! HEY HEY!"

Obviously, I'd be lax if I didn't mention Kefka's laugh...

Most memorable? Probably Sonic's rings.

Oh, daaaaamn! Absolutely. Seconded.

Falling to your death in the C64 version of Impossible Mission

"HOLD IT!" 
"OBJECTION!" 
"TAKE THAT!"

I would have to recheck my rolodex of video game sound banks that resides deep in the recesses of my mind, but currently the chanting of "EBA" toward the ending of Elite Beat Agents is up there as one of the greatest moments of gaming ever.

The "splat!" sound from Secret of Evermore

Oh, and Syldra's wailings from FF5! The same sound, yet life affirming or devastating depending on the context...

Totatally agree with you on this one, it always sounds like 'Go-ges-lo-Go-ges-lo..' to me but these things are always open to personal interpretation anyways.
( ;

A couple of my all-time faves are the 'whip' sound effect from Streets of Rage 2, the 'tidal wave rise & crash' sound from Super Ghouls n' Ghosts, the 'splattering' sound of blood globs hitting the pavement in Mortal Kombat 1, and the 'burst' sound of a chaff grenade detonating in MGS.
Oh yeah and the 'b-beep, b-beep' sound of those 5-Second time bombs counting down (from that skeletoid boss in Contra III Alien Wars).

Voice samples, well my latest one has been that 'he-heh-hah' noise that Haggar makes when he flips someone over to piledrive them into the sidewalk. Other faves, um..
'NOOOOOO!!' from Perfect Dark (N64), practically everything from the Samurai Shodown series, Dracula's dying words in the Prologue to Symphony of the Night ('No.. It cannot be! AAAAAAHHHH!!' *poof*), ..and that japanese word of approval that the gym teacher character in Rival Schools says in the training mode whenever you follow his directions properly.
Oh, just remembered.. from MegaMan X4, the 'Hoo-ha-hooah' from Zero when he swings his sword three times in a row, and also, the campy 'Whoa, JUUUUMP!!' from the opening sequence of Brave Fencer Musashi.
And one more, 'ACTION!!' from Time Crisis One

Whew!

Often overshadowed by Cefca's but just as cool (and kinda funny too), the Grim Reaper's cackle when the Death spell carries your soul away..

I still like her 'Watchout!' a lot though, heh

Coin sound, Super Mario Bros.

Hitting a Charging Chuck in Super Mario World.

Stepping on an enemy in Super Mario Bros. 1 & 3.

The Sonic ring noise... I'll second that.

The Donatello "bow", Leonardo "sword slash" and that damn hit noise from TMNT.

Rockman Mega Man (FC/NES) series; Hitting the ground after jumping, shooting, and of course, the taking damage sounds.

Too many more...

Yep, that's a VERY memorable and distinct sound, and even non-gamers recognize it.

Most memorable to me is the OneUp Sound from Mario and the 'you discovered a secret thing!' jingle from Zelda.

id like to submit a contender for the most annoying voice-bits: Nigel Mansell's championship racing for snes... his annoying choppy voice would say 'left' and 'right' when you were approaching turns...

Megaman 1 & 2's death sound, butchered thereafter (*DUNNHdunnhdunnhdunnh*)
Zelda 3's dying boss (*eh-WEHW-eh-WEHW-eh-WOOHHHW*)
Super Metroid's Baby Metroid pulse (*eeEWWH...eeEWWH*)
FF4's Virus spell (*NN-UHrrINNEENG*)
FF7's Limit Break (*kshWAAAAA*)
Megaman X6's stage kick-off ("READY?!"...spoken in a you-only-think-you-are tone)
Metal Slug's fatty announcement ("Whoa-ho! BIG.")
Viewtiful Joe's battle kick-off ("Just GO for it!")
Devil May Cry's Sin Scythe cackle ("Ha-haHAHA-ha-ha-ha-ha!")
and yes, the Phoenix Wright calls, as Angela mentioned.

I'm probably forgetting a squillion, but they'll come to me eventually.

Not a Navi sound, but we MUST remember Link's "skank!!" from OoT. And I also must agree with Kefka's laugh.

I know there are tons of other sounds I'm forgetting...

Forgot about that one! I always exclaim that whenever I'm around people, in my car... that and "HEAVY MACHINEGIN!"

Nothing beats that good ole "Rocket Launcher!" with Launcher pronounced as 'Lownchah'

Lawn chair!!

heheh

Yeah the FF sfx guys were always on top of their game, their extremely creative sounds helped sell many a SFC..

Other FF4 favorites of mine were the metallic 'boink-boink' when whacking an enemy with a staff, the 'twinklestar-spritey' Comet spell's sound, and the alltime classic 'clock slowing down' for..
wait for it.. Slow.

And even though it's a horrible port, I still can't get the Battle Encounter sound effect they added to the ps1 version of FF6 (fft-ftt-fwww).