[Gortef]

Grim Fandango has great lines too... actually any Lucas Arts adventure game has good lines.

[General Freak]

Manny Calavera:
You can't hide from the Grim Reaper. Especially when he's got a gun

[Roanoke]

Planescape: Torment has some good stuff.

[ToecrusherHammerjaw]

All your base are belong to us!!

Hey, it counts.........doesn't it?

[Mr. Vega]

Thief-- Any line by Garrett. Or Benny.

"I don't expect to run into anything more threatening other than a few venomous spiders.....however the map does contain this note: 'Stand not against us, lest you feel the stings of ignorances barbs'.....sounds like keeper talk for 'We've rigged the place!'"

[Fineus]

Duke Nukem. Half Life. Black and White.

[ZylonBane]

All of Duke Nukem's best lines are stolen from other sources.

[ZmaN]

I think Homesick had some GREAT voice acting (the first few missions, when everyone is ranting eachother to death, and alpha 3 is complaining because he wants beta 4's seth fighter. it made me lauch so hard).....

Other than that, I'd have to say Tribes has some funny lines:

Daniel:  and your a Spoiled Brat!
Julia:  If thats what it means to be a Pheonix, then COUNT ME OUT!

Also, Doyle in Far Cry:  You seem to have  an act for blowing things up, Jack...
Sam Fisher has ALOTTA lines that I like.....

I cant remember anymore....

Ill post more as I remember...

[ZylonBane]

Also, Doyle in Far Cry: You seem to have an act for blowing things up, Jack...

"A knack", genius.

[CaptJosh]

"I'm a doctor, not a target!" --Leonard "Bones" McCoy" in Star Trek: Judgement Rites when you try to use a phaser on him sometimes.