GET OVER HERE!

One of my favorites has to be a seriously badass boast from Alex Mercer to Colonel Taggart in [PROTOTYPE]: "NOTHING CAN PROTECT YOU FROM ME! NOT MEN! NOT WEAPONS! NOT ARMOR!"

Even more awesome is the following quote when Taggart brings out a pathetic three tanks to try and stop Mercer: "LIKE IT'S GONNA MAKE A DIFFERENCE!"

"I used to be an adventurer like you, then I took an arrow in the knee."

Cliche - buuut, Skyrim is an amazing game so it was only obligatory to mention. :]

"I could be dead by tomorrow morning. Should have changed my underwear." Kamille Bidan in Dynasty Warriors Gundam 2
"What a horrible night to have a curse" Simon's Quest
"You and your friends are dead. Game Over." Friday 13th
"We've managed to avoid drowning." MGS2
And many more I can't think of right now.

"So admit it..... Don't I look cool in the game screens? Those long, muscular legs on my sturdy toned frame.... I'm the perfect specimen of a man ..... What!?!? You say I look fat and my quadruple chin looks like a waterfall of flab? Shut up! That's just because you have your television set up on widescreen display!" - Wario (Wario World)
"Should've been called WARIO Golf! Still, you gonna love it!" - Wario (Mario Golf)
"I pounded down a healthy cup of sugar (with just a dash of coffee) for breakfast." - Wario (Warioware Mega Micro Games)
"H-H-H-HURRY UP!!!" - Wario (Wario Land 4)
"It's-a Wii! Wario!" - Wario (Warioware: Smooth Moves)
"Behold the TELMET! Television! Teleportin'! And, uh, it's a helmet." - Wario (Wario: Master of Disguise)

Basically anything Wario, really.

Also this is a great one from Kid Icarus Uprising. Not exactly a quote, but still.
Pit: "Yeah, I know, I used them in the last brawl."
Palutina: "Brawl?! How horrible! Are you hurt?"
Pit: "No way! It was a SMASH!"
Palutina: "I just can't imagine YOU in a Melee!"
Pit: "...That's because I wasn't"

EDIT:
A recent one that I liked:
"I think it's time for Jack...to let'er rip!" - Raiden (Metal Gear Rising)

"Oh hey, its that dog!"
"Well, I see that the President has equipped his daughter with ballistics too!"
"Where's everyone going, Bingo?"
From the amazing masterpiece of game dialog that is Resident Evil 4. If you don't know why these are hilarious, the way they are said is amazing.

Well, I don't know if the following are my favourite, but they have thus far been very memorable to me:

"DO NOT TEASE THE OCTOPUS" - Ultros (Final Fantasy VI)
"..." - Cloud (Final Fantasy VII)
"Don't you need my brain power?" - Lucca (Chrono Trigger) ~ More like fire power.
"HEY! LISTEN!" - Navi (Ocarina of Time) ~ Probably my least favourite quote.
"Snick! My switch was turned on!" - Burgh (Pokemon Black/White) ~You won't believe how hard I LOL'd when I first heard this.
"This is bad! Bad for Team Plasma! Or Plasbad, for short!" - Team Plasma Grunt (Pokemon Black/White)
"I like shorts! They're comfy and easy to wear!" - Youngster (Pokemon Red/Blue/Yellow)
"Everyone has psychic power. People just don't realize it." - Sabrina (Pokemon Yellow/FR/LG)
"You're too slow!" - Sonic (Super Smash Bros. Brawl)
"Spankety, spankety, spankety!" - Porky (Earthbound)
"here goes no something." - Mr. Saturn (Mother 3)
"we are fulgrate." - Mr. Saturn (Mother 3)
"All the info is there, except for the info that isn't there." - Librarian (Earthbound)
"Yesno, you will won't." - Moonside resident (Earthbound)
"It can dry anything in mere minutes, even long hair, afros, panties, and Asian beauties!" - Dr. Andonuts (Mother 3) ~I know it's racist, but still, LOL.
"YOU REAP WHAT YOU SEW-SO-SO GREETINGS CHEESE POPSICLE THE NUMBER YOU HAVE DIALED IS CURRENTLY OUT OF PORK CHOPS FROM EAST TO WEST IT GOES GOES BROKEN BROKEN OH SO-SO-SEW BROKEN..." - Miss Marshmallow (Mother 3)

I like shorts they're comfy and easy to wear!

"TURTLE!" (Exdeath: Dissidia)
"The defence would like to cross examine the witnesses pet parrot!" (phoenix wright)
"What is a man? A miserable pile of secrets! But enough talk...have at you!" (Dracula: Castlevania Darcula X Rondo of Blood)
"Suffer and suffer well so I can savor your misery!" (Yo****sugu Otani: Sengoku Basara 3 Samurai Heroes)
"Hey by the way... Do you know what the fine here is for necrophilia? I would like to know." (Hinalu Hlaalu: ((or what ever is her name alchemist in Skingrad)) Oblivion) That last one always shocks me. I mean...why.
.is...it...in..the...game?

Anything from Star Fox 64, really. Most quotable game of all time, lol.

"You can't beat me! I've got better ship!"
"I can't believe I lost to this scum!"
"Daddy screamed really good before he died." (anything Pigma says really)
"Never give up. Trust your instincts."
"Annoying bird. I am the great Leon!"
"Cocky little freaks!"

"So you have a girlfriend, mate? I bet she has a fine beard." (Radiata Stories) :laugh:
"You cannot grasp the true form of Giygas' attack!" (Earthbound/Mother 2)
"Then put down your sword. As a descendant of Baldo, the crusader of light, I will not betray you." Sigurd (FE4)
"Why, when we all desire the same results, do people choose such different paths?" Ashley (Wild ARMs 2)
"Pick a god and pray!" Fredrick (FE13)
"Fate has no forgiveness for those who dare stand against it." (Chrono Cross game over screen)
"It shall be engraved upon your soul!" Lenneth (Valkyrie Profile)

"This is my Story" - Auron, FF X
"Got it memorized?" - Axel, Kingdom Hearts II

"And then, we can go see Santa! Erm...but first, the Heartless!" - Sora, KH II
"is this a dream....or is it...real?" - Sora, KH II

"Whaddya say to one last showdown?" - Ocelot, MGS3
"I see you" - The End, MGS3

One of my favorite lines would have to come fro, from Warcraft 3 Frozen Throne where the demon assisting Sylvanas says the line "Wake up, time to die." when he's going to attack an enemy nearby.

Well, here are some of my favorite quotes:

"All your base are belong to us." Zero Wing, as shown by Fabio.

"Your welcome Dizzy Devil." Tiny Toon Adventures Buster's hidden treasure, probably what started the Your and You're grammar error.

"Friendship... Friendship? again?" MK3, I thought this to be quite funny after Shao Kahn said it with surprise.

"Doug Duem! Don't think I'm going to bend over for you!" Digimon World 2. I didn't understand this at first, but boy did I laugh a lot when I replayed this again XD

"Cynthia... are you okay?" Silent Hill 4. I was waiting for Cynthia to say "I'm fine" or something like that because of all the blood in the room. Harry, you don't say?

"Well, if it isn't that b**** in the red dress." - Jack Krauser; Resident Evil 4

"You may be able to prolong your life, but it's not like you can escape your inevitable death, is it?" - Jack Krauser; Resident Evil 4

"Your right hand comes off?" - Leon Kennedy; Resident Evil 4

"Goddammit, I trusted you! F*** you... and f*** your Marker!" - Isaac Clarke; Dead Space 2

"You can't spell assassin without sin... and twice the ass!" - Deadpool; Marvel Vs Capcom 3

"Down, Sword Hand!"- Owain; Fire Emblem: Awakening

"This city have very yummy sand! This city delicious!"- Quina Quen; Final Fantasy IX

"Aiya! What big stone! Why you all watch stone? Is stone edible? Or is for barbecue? No answer... I think I lick it."- Quina Quen; Final Fantasy IX

"There are ants on your feet. Please don't continue in that direction, as you might step on them.'' Mother 3.

"You're not me!" Persona 4.

Pretty much anything that was Tales of related:

"Repede's male..." - Yuri Lowell (Tales of Vesperia)
"Oh yes... OH GOD YES!" - Raven (Tales of Vesperia)
"Prepare to die, eggbear!" - Yuri Lowell [in Karol's acted voice...] (Tales of Vesperia)
"Well said... I will make those words your last, REPLICA!" - Asch, the Bloody (Tales of Abyss)
"Victory! Belongs to! The most! SEXY! Dead sexy!" - Zelos Wilder (Tales of Symphonia)
"I lied. The coffee was actually hot." - Lloyd Irving (Tales of Symphonia)
"Too... much... Testosterone! Can't breathe!" - Zelos Wilder (Tales of Symphonia: Dawn of the New World)
"No, he's crazy on the inside too..." - Luke fon Fabre & Guy (Tales of Abyss)
"This was an item from the heavens!" - Ange Serena (Tales of Innocence)
"A sighs four, that is!" - Tenebrae (Tales of Symphonia: Dawn of the new World)
"That damn exercise machine must of been a scam!" - Decus (Tales of Symphonia: Dawn of the new World)

But, I do also love the quotes from Kid Icarus Uprising:

Palutena: I'm sensing treasure somewhere to your left.
Pit: How do you know that?
Palutina: From the heavens, I can see through your laurel crown to divine your surroundings!
Pit: Really? That's amazing!
Palutena: And that's not all I can see, Pit. I can also see what's in your heart.
Pit: Oh...Heh heh...That's really...something.
Palutina: So you better not be thinking anything... naughty!
Pit: What!? How did you--
Palutina: Just kidding! Seriously, reading hearts through laurel crowns?
Pit: I know...I was...also...kidding.
Palutina: Sure you were.

"Metal gear" -Solid Snake

ON MY MARK, SHAKE IT FOR GREAT JUSTICE
/dance

Combining characters' lines with the right timing makes for the most amusing quotes. The Tribes games have the best potential for this.

Curious. said:

"I used to be an adventurer like you, then I took an arrow in the knee."

Cliche - buuut, Skyrim is an amazing game so it was only obligatory to mention. :]

Click to expand...

"What is better — to be born good, or to overcome your evil nature through great effort?" — Paarthurnax
In all seriousness, it's a great line given the context.

"When life gives you lemons, don't make lemonade. Make life take the lemons back! Get mad! I don't want your damn lemons, what the hell am I supposed to do with these? Demand to see life's manager! Make life rue the day it thought it could give Cave Johnson lemons! Do you know who I am? I'm the man who's gonna burn your house down! With the lemons! I'm gonna get my engineers to invent a combustible lemon that burns your house down!"

Cave Johnson. Portal 2.