Kasumi

Kasumi: "EDI has a wicked sense of humor. Or perhaps a very funny lack of one. She seems human at times, but I can't get past the fact that she's a computer."
EDI: "You humans are all racist!"

What? This doesn't make any sense.

Garrus: "Oh no! Our engines are freezing!"
Shepard: "The last node is right up there! Why can't I jump any higher?"
Garrus: "Because the engines are overheating!"
Shepard: "I thought they were freezing."
Garrus: "Well, yeah. They're overfreazting."
Shepard: *facepalms* "Never mind, I'm only getting 125 xp for each of these minigames anyway."

I hope someone gets this...

Grunt: "Uh, listen, human. You said 'bell peppers and beef." There's no beef in here. So you wouldn't really call it 'bell peppers and beef,' now would you?"
Mess Sergeant Gardner: "Yes, I would."
Grunt: "Well, it's not!"
Gardner: "It is when you're broke! Shepard can't afford the 560 credits for the gourmet food supplies I asked for?"
Grunt: "What happened to the 30,000 credits Shepard got paid for the last mission?!"
Garnder: "The 60 probes she fired at Uranus..."
EDI: "Seriously."
Garnder: "And space ship models she keeps buying... and the fish that keep dying... KILLED THE DOUGH!"
Grunt: "Hmmph. I'm going to Shepard's cabin. I've always wanted to eat a fish from the captain's quarters."

Call whine one one and ask for a waaaambulance.

Kelly: "Jack would like to see you, Commander."
Shepard: "Shit."

Jack: "I've got thoughts, like little bugs crawling around in my head."
Shepard: "Wah, wah, wah. I've got a whiny punk, like a little bug crawling around in my ship. What do you want?"
Jack: "Cerberus did experiments on me. They drugged me, tortured me. Whatever chance I had to be normal, they stole from me by trying to turn me into a super-biotic. The doctors, the other kids, they all hated me. They let me suffer."
Shepard: "And now you're a super-biotic. Cerberus lured thresher maws to my units' position. Out of the fifty Marines there, I survived, along with Corporal Toombs, who was captured by Cerberus. He went insane. They put thresher maw acid in his veins. I have nightmares of my fellow Marines getting ripped to shreds. Every night. I don't shave my head or go berserk with the ink. I deal with it."
Jack: "There was some kind of emergency. I got out. Everyone tried to stop me; the other kids, the guards. I killed everyone in my way and ran. I was picked up by slavers. They used me, then they sold me. There's my uplifting escape story."
Shepard: "Batarian slavers attacked my home. They killed my parents, my brother and sisters, and everyone I knew. At least, I hope they did. I met a girl they captured. She blew her brains out right in front of me. And besides, why didn't you just use your super biotic powers to kill the slavers that tried to use you? You fought your way out of a Cerberus base, but then got pwned by some two bit slavers? Whatever."
Jack: "I want to go to my cell and set a big bomb and set it off and watch from orbit!"
Shepard: "Well, you're batshit insane, but Cerberus deserves it. Fine."

(After the mission)

Shepard: "So, it seems Cerberus used the other kids as test subjects so they wouldn't hurt you. Dozens of children were murdered to keep you safe as they made you into uberbiotic. How does that make you feel?"
Jack: "No! No one had it worse than me! I'm the most shit-on little girl in the whole wide galaxy!"
Shepard: "Whatever you have to tell yourself to keep yourself half-sane. Anyway, you're the one who wants to live in the bilge with the leaky sewer pipes. Don't pester me again."

Oh, Jack. How long were you in cryo?

Jack: "I like your ship. I wouldn't mind putting it through its paces when you're not around."
Shepard: "Even though I'm not around a lot, since I never take you on missions because you're pretty much worthless, you're crazier than I thought if you think you can try."
Jack: "If I wanted it, I'd take it."
Shepard: "Look, bitch. Let's get one thing straight. You're on this ship because I wanted the shotgun damage upgrade and level up from recruiting your bald, "look at me I want to be the center of attention"-tattooed, anorexic jerkass. An asari commando has had at least a century to study fighting, from hand-to-hand, to firearms, to biotics that make your wimpy shockwave look like a parlor trick. I've killed more of them than you've killed erections. Don't ever think you'd be more than a minor speedbump if you ever got in my way."

Logic 101

Mechanic: "The Collectors? They're real? They took everyone! This is all the Alliance's fault!"
Shepard: "What?"
Mechanic: "No one bothered us until the Alliance put in those defense towers!"
Shepard: "Correlation doesn't imply causation."
Mechanic: "Huh?"
Shepard: "Post hoc ergo prompter hoc is one of the oldest logical fallacies in the book. Just because A happened, then B occured, does not mean that A caused B."
Mechanic: "But..."
Shepard: "No other colonies that were attacked had any new Alliance defense towers."
Mechanic: "But that Chief Williams showed up, then we were attacked! She was on Eden Prime, and they got attacked, too!"
Shepard: "Well now you've at least got two instances, which is a stronger argument. But look at the other common factors. Each human colony attacked, including Eden Prime, Horizon, and Freedom's Progress, were outside of Citadel Space. The ones attacked most recently are outside Alliance space. Isn't it more likely that building a colony outside of the borders of a government which might be able to protect you could lead to an opportunistic foe attacking you?"
Mechanic: "It's the Alliance's fault!"
Shepard: "... OK, sure, whatever. Look, we can use the guns."
Mechanic: "They need to be calibrated. They've never worked before!"
Shepard: "Thus, they'll never work? Seriously, do you even hear yourself? Have you ever been attacked by Collectors before? No? So, that means they should never attack you, right? Wrong! Just because something has never occurred, does not mean that it will never occur."
Mechanic: "It's still the Alliance's fault."
Shepard: "But... *sigh* Shut your pie hole, open the door, and stay out of my way. Dumbass."

On Therum

Joker: "Commander, I'm picking up some strange readings. Like, really strange, off the damn charts. It's coming from an old mine."
Shepard: "What do you mean, off the charts? Switch from linear to logarithmic."
Joker: "Oh. Um... lemme... OK, yeah. 3.2e14."
Shepard: "What? 3.2e14 of what? Meters? Watts? Kilograms?"
Joker: "Just... you know, strangeness."
Shepard: "What the fuck are you talking about, strangeness? There's no SI unit of measure for 'strangeness.' What sensor are you using?"
Joker: "I don't know, I just pressed some glowy buttons and some lines came up."
Shepard: *disconnects*
Joker: "All right, back to Galaxy of Fantasy."