Leonard: Look, if you want to break up just say it.
Penny: Leonard ...
Leonard: No, I take it back, don't say. Just hate me but stay wiht me. It worked for my parents.

Leonard: Oh, okay. Good, good. So it's cool if I cry a little?
Penny: Yeah, I probably wouldn't.
Leonard: Yeah ... *wipes tears from his right eye*.

Penny: Great, because I've been thinking if I really want this acting thing to work, I need to focus all my energy on it. And to do that, I should quit waitressing at the Cheesecake Factory.
Leonard: Wow, that's a big step.
Penny: I know.
Leonard: So before making any rash decisions.
Penny: I already quit.
Leonard: And I support you!

Leonard: (on the phone) Yes, how much for 100 long-stem red roses? Really? How much for three?

Leonard: I'm so proud of you.
Penny: They haven't even got to my scene yet.
Leonard: I know, but you're going to be a TV star and you haven't left me yet. That takes guts!

Sheldon: Leonard, do you think I'm funny?
Leonard: No. Do you?
Sheldon: I think I'm hysterical.
Leonard: I take it back. That was funny!

Leonard: He made you his screensaver.
Amy: Oh, wow. I had no idea. He is so into me!

Raj: At least Leonard, Howard and I would have always been friends.
Bernadette: Hey, how come you three never got an apartment together?
Leonard: We talked about it, but Howard was in a pretty serious relationship ... with his mom.

Leonard: Uhh, umm. I'm Leonard.
Penny: Really? You don't sound so sure.
Leonard: No, I am me.

Penny: Do you ever imagine what that would be would be like, not being born?
Leonard: *Sheldon's knock* What do you think? *Sheldon's knock* What do you think? *Sheldon's knock* What do you think?

Leonard: All right, here's the deal. Sheldon is gone so the tree decorating rules are out the window.
Penny: Which means we don't have to use his ridiculous ornament spacing template.
Leonard: And I'm happy to report its Kickstarter campaign is holding steady at $0.

Raj: So Star Trek and Star Wars characters can go on the same branch?
Leonard: I know, it's crazy. Welcome to the Thunderdome, people!

Leonard: Oh, I forgot about this (sweater). My aunt made it for me when I finished college.
Penny: Aww, did she hate you?
Leonard: Why because I got an ugly, itchy sweater and my brother got a car? No, I was her favorite!

Leonard: So when you say you're not going to flip out about the DVD, here's what that means. Don't fixate on it, or wake me up in the middle of the night, or nag me through the door while I'm on the toilet.

Professor Proton: Can I ask you a question?
Leonard: Yeah, sure.
Professor Proton: Why do you put up with Sheldon?
Leonard: Oh, you know because we're friends.
Professor Proton: Why?
Leonard: Wow, you ask really hard questions. Look, I know he can be aggravating, but what you have to remember is he's not doing it on purpose, it's just how he is. But he's also loyal and trustworthy and we have fun together.
Professor Proton: You know you're describing a dog?
Leonard: He did bite me once. But in his defense, I came up behind him while he was eating.
Professor Proton: They hate that.
Leonard: Sheldon is the smartest person I have met. He's a little broken and he needs me. And I guess I need him too.
Professor Proton: Why is that?
Leonard: Boy, you will not let this go, will you?