Season 3, episode 6
Leonard: How was your football party?
Penny: It was, pretty good. We won!
Leonard: Oh, that's excellen! It's a weird figure of speech, isn't it. "We won", when you're not actually playing. When we watch Star Wars we don't say: "We defeated the empire"
Penny: I'm glad to hear it!
Penny: Look, if you wanna meet my friends that'd be great. I just, I didn't want you to be bored.
Leonard: I wouldn't be bored. Why would I be bored.
Penny: Well, because they're not genius scientists.
Leonard: Penny, I like all sorts of people. Some of my best friends aren't geniuses.
Penny: Like who
Leonard: (very long pause) Ok, some of my Facebook friends aren't geniuses.
Howard: Rasj, what are you doing here. You're supposed to be helping me pimp up my Vespa.
(long whining conv about a girl)
Rasj: Fine, paint green flames on your little scooter with her.
Howard: It's not a little scooter. It's the second biggest Vespa they make!!
Howard: Sheldon knows football?
Howard: I mean, Quidditch sure - but football?
Leonard: Sheldon, how do you know this stuff?
Sheldon: I grew up in Texas. Football is ubiquitous in Taxas. Pro football, college football, high school football, peweee football. In fact every form of football except the original; European football.
Sheldon: If you're interested I also know all about frying meat that isn't chicken as if it were chicken
(starts with more whining the girls Howard couldn't get)
Rasj: You're impossible
Howard: Well, at least I can talk to women without being drunk
Rasj: Excuse me. I have selected mutism, a recognized medial disorder. You're just a dush.
Season 3, episode 7
Penny: And FYI, you never even heard of the Black Eyed Peas before you met me
Leonard: Oh, I heard of them!
Penny: (leaves the room)
Leonard: Didn't know they were a band
Leonard: Come on, this is stupid
Penny: Oh, there it is again. You think I'm stupid
Leonard: No, there's a difference between being stupid and acting stupid
Penny: Oh yeah? Well, there's a difference between being a jerk and being an ass
Leonard: (shouts up the stairs) No there isn't, they're synonyms
Sheldon: Leonard, when that woman moved in three years ago I told you not to talk to her and now look, we're going to be late for the movies
Leonard: Where are you going? You can't just walk away in the middle of an argument.
Penny: No, I'm gonna go find your damn roommate before he hurts himself trying to cross
the street or something.
Leonard: Why didn't you say so?
Penny: Oh, now I need your permission for that too?
Leonard: I can't read your mind, Penny!
Penny: Really, why not? You're so smart and I'm so dumb.
Rasj: Please tell my parents that my dark matter research is at a critical juncture, and I can't home for my cousin Sanjay's wedding!
Rasj's mother: Sheldon, ask our son what we're supposed to say to mister and misses Chouldry who's daughter likes him and is flying in from London for the sole purpose of meeting him.
Rasj: I didn't ask you to set me up with Lakshmi!
Rasj's mother: You should be thanking us!
Rasj's father: Yes, Lakshmi just got her stomach stapled. You have an opportunity of getting good with her before she loses weight and her self-esteem goes up!
Rasj: I don't care. And why don't you think I can find a woman for myself
Rasj's mother: Because you're twenty-seven and the closest thing we have to a daughter-in-law is that Jewish boy Howard.
Lenny: (whistles out of the car window, in search for the aforementioned roommate Sheldon)
Leonard: What are you doing, he's not a lost dog?
Penny: Hey, why don't you just let me find him while you sit there hitting your imaginary break!
Leonard: The break might be imaginary, but that stop sign you just ran wasn't!
Penny: What stop sign? (looks back)
Leonard: Eyes on the road, EYES ON THE ROAD! (grabs the roof of the car)
Penny: Alright, what's going on?
Leonard: It's a little hard to explain. He does this thing where he pretends to be in an alternate dimension that occupies the same physical space we are in, but he can't perceive us
Sheldon: Don't flatter yourself, I'm just ignoring you
All through the episode, people have been fighting and Sheldon has been running away from it and/or making loud noises to make the fights go away. Apparently he has some issues with that, apart from all the others. Eventually, Penny manages to calm him down with some gifts.
Another red line through the episode was Penny and Leonard's fight about an ex-boyfriend of Penny's coming over and her planning to let him sleep on her couch. The socially disabled and very much not-fine with this Leonard has been acting out rather jealous. But, all's well that ends well:
Leonard: So, what did Justin say when you told him he couldn't sleep on your couch?
Penny: (cuddling up to Leonard) He's a musician, he'll sleep in his own vomit if he needs to
Sheldon: (sits in his living room on his spot on the couch, looks to his right upon a sleeping Justin) I should have asked for a lot more than a comic book and a robot!