An older Courier on hearing about the Lonesome drifters daddy issues, with the Ladys man perk "You're not 17 are you?"
Drifter " No 28, why?".

"Hey man when in Rome"

"They asked me how well I understood theoretical physics. I told them I had a theoretical degree in physics. They said welcome aboard."

"Guess who just got promoted to the [censored] dam God?"

I WON THE MOTHER F-KIN LOTERY!!!

Oh is it a dress?

The game was rigged from the start.

It sets the mood for the game right from the start .

"Heeeeeeeeeyyyyyyyyy-Ooooooooooooo"

LOL!

Gomooorah, it will be our secret.

"Ta-Ta" - Benny

"So? What'd you find down there...?" - Benny

"I'M GONNA [censored] YOU UP [censored]!" - Some [censored] up Fiend

Did I stutter [censored]tard? - The tops promoter after doing the Tops entertainment quest.

Lily:
"Oooh! Look pumpkin, a dinosaur! Do you want to ride the dinosaur?!"
"GRANDMA'S GOT A PRESENT FOR YOU!" -> Actually, Lily, pretty sure I'm giving you the present... A BRAND NEW REBAR CLUB!!
"DON'T WORRY ABOUT ME, HONEY! YOUR GRANDMA KNOWS HOW TO STAY QUIET!" -> while attempting to sneak

Veronica:
"Does jumping at them with my fists count as a 'ranged' weapon?"
"Got something good for me? *excitedly* Is it a dress?!!"

No-bark:
"It's ghouls I tell ya, religious ghouls in rockets, looking for a land to call their own" -> Which is strange considering earlier he tells the Courier he doesn't believe ghouls live nearby and that it's rather commie ghosts.
"So I says, Well then, we got a chupacabra with an automatic weapon on our hands. And thats when they got real quiet, cause then they saw the predicament we was in."

Fantastic:
"They asked if I had a degree in theoretical physics. I told them I had a theoretical degree in physics. They said welcome aboard."

I was actually pleasantly surprised regarding the companion interaction.

"How about I aim my gun at you for a while, see how you like it"

:laugh:

"When I find you...I'm gonna eat your spleen!"

Seriously, have you ever snorted a ground up Cazador venom sack? Neither have I, but I assure you a Freeside junkie has. - Arcade Gannon

Right now, I'm sure you're asking yourself, "Why hasn't some lucky man scooped this bachelor off his feet?" Like I said, I'm boring. - Arcade Gannon

Rhonda: We'll be right back after this word from our sponsor, during which Raul will contemplate how LUCKY he is to be alive!

"how bout I aim my gun at your head for a while?-Boone
"Shush, we're hunting [censored] heads" -Cass while sneaking
"Don't worry deary your grandma knows how to stay quiet" -Most annoying Companion ever
"The asked me what I knew about theoretical physics, I said I had a theoretical degree in physics" -Fantastic

I'm missing qupting but basically "Oh wow, really? That's great news, despite my predictions that they'd be our greatest challengers!" -yes man

Best New Vegas lines to me are pretty much anything No-Bark says.

Favorite Fallout 3 line has to be from the Republic of Dave tour ...

"Mounted to my left is the very head of the slain deathclaw Dave encountered during his quest through the wastes. I know what you're thinking and no, that's not a brahmin skull. Brahmin have two heads, so there'd have to be two skulls for it to be brahmin."

Fiend - "You like the sight of your own BLAD?!"

^_^

Little Buster: " I'm all about risking my life but I'm a little sensitive about my @$$hole."

The whole conversation with this guy when you first encounter him is pretty hilarious.

Arcade: There's something about that robot that doesn't seem... all right to me. I'm not saying we shouldn't take it with us. I'm just saying if it were to fall into Lake Mead anf it were to be irrepairably damaged... and if you threw an EMP grenade in after it. Well, there are worse things happening in the world, right?
Courier: What's your problem with ED-E?
Arcade: It just seems a little twitchy. Some of these robots, you look at them the wrong way, don't screw in a vaccum tube right... The next thing you know, you're a pile of ash on the floor and someone's stepping out of a Vertibird to sweep your remains into a Nuka-Cola bottle.
Courier: I'll keep an eye on it, all right.
Arcade: Safety first. That's all I'm saying.

-Arcade Gannon to The Courier after recruiting him with ED-E present.

Holy Poo! I did NOT expect my first thread to go on that long. I figured 2-3 days tops. I only have that one favorite line from New Vegas, but my favorite from FO3 has to be 'You stay away from the generator room!' Just the way it was said, I found myself laughing for ages.

Chris Haversam: Who's going to work on the reactor? Gunderson? Hendricks? No, let HAVERSAM do it! He likes machines! Haversam won't mind getting irradiated! Haversam won't mind his hair falling out after a few months! There's no connection Haversam, you're just being neurotic!
Courier Six: You left your vault because you were going bald?
Chris Haversam: Bald? BALD!? I'm a monster! A monster!

Best Friend Tabitha: CENTAURS! EAT! HUMANS!
Rhonda: Ahhhh, that *would* make it hard for them to communicate! (or something to that effect)

Rhonda: Safety not guaranteed from Two-Headed Bear People or Battle Cattle!

Fantastic: We're getting power, because the guy who runs this place is Fantastic!

Veronica: Yeah... I guess it works.

Nightkin: So many starin' eyes! (just the way it's said)

Mutant, in the peaceful, diplomatic Jacobstown: You think Marcus could get us some miniguns? Or MISSILE LAUNCHURS?!

"If you're traveling with Veronica make sure to bring a set of ear plugs. Just kidding Veronica, put the power fist down."

You eyeballing me? funny after hearing it every time you go near a powder ganger.

"Petro Chico! Petro Chico Boy esta aqui para mis chicharonnes! Oh, just a dream. Just a dream."- Raul after revival from unconcisouness.

"Sure boss. I'll just stop using my rather effective gun and switch to this uh piece of metal tubing here. Great plan boss!"-Raul when switching to melee.

Raul and Veronica in general are hilarious

Me: -gives guns to Tops doorman- Where'd you take my guns?
Tops guy: Relax baby, they're safe as houses.
Real me: -laughs for 10 minutes-

Oh, I forgot one:

"Clearly this is the best tactical choice if you want me to die very rapidly"

^Arcade, when you tell him to use Melee Weapons.

"Are you [censored] kidding me? First I get my legs smashed, and then in walks the Powder Gangers' grim [censored] reaper? What the [censored] have you got against us man?" - Boxcars

FO3 Raider: You dont like the sight of you own blood?
NV Fiends: You like the sight of you own blood?