Big things are happening on TV Tropes! New admins, new designs, fewer ads, mobile versions, beta testing opportunities, thematic discovery engine, fun trope tools and toys, and much more - Learn how to help here and discuss here.
Sheldon: Little Miss "grown-ups don't play with toys"! If I went into that apartment right now, would I not find Beanie Babies? Are you not an accumulator of Care Bears and My Little Ponies? And who is that Japanese feline frolicking on your shorts? Hello, Hello Kitty!
Leonard: That's right, you saw what you saw, that's how we roll in the Shire.
Sheldon taking on Leonard, Howard, Raj and Leslie Winkle in the physics bowl and fighting them to a draw. Although he was portrayed as the villain of the episode, it's one of the few times he shows that he is every bit as intelligent as he's made out to be.
Penny calling Sheldon out on his refusing to go to the hospital to support Howard after his mother suffers a suspected heart attack, pointing out that he constantly wears superhero t-shirts, but refuses to go to the hospital to support a friend.
Also a Funny Moment, as Sheldon, who is more or less agnostic, pulls out a parody of the Crucified Hero Shot and after he "dies" says, "If there is ever going to be a Church of Sheldon, this is where it started".
Bernadette realizing she was in the wrong and trying to make it up to Howard.
Howard himself deserves a lot of credit for actually kicking her out of the house when she "tattled" to his mom about the issue because she had crossed the line, and freely admitted to the others they might break up over the whole thing. Coming from a guy who normally lets women walk all over him so long as they have sex with him, that showed a great deal of personal integrity.
Even his friends are suitably impressed.
Raj: Not only are you the first one of us to get married, you're also the only one of us to kick a woman out of bed. You're like a rock star!
Sheldon successfully pranking Leonard in such a awesome and hilarious way after getting pranked by Howard, Raj, and Leonard repeatedly throughout the Halloween episode.
Leonard's opening lines in his imagined date with Penny are awesome in their own way - he's confident, charming, and even flirts a little, showing just how much of an impact Penny has made on his social skills:
Leonard: So, Polly, tell me about yourself.
Penny: It's Penny.
Leonard: Oh sorry, yeah, awkward...
Penny: Okay, uh, let's see, I'm from Nebraska, and ever since I was little girl I dreamed of moving to L.A. and becoming a movie star. Anyway, after four years of acting lessons and waiting tables, I've done a hemorrhoid commercial and a production of Anne Frank above a bowling alley. So, you know, dreams do come true! Your turn!
Leonard: Ah, let's see. I am an experimental physicist at Caltech. Most of my research is with high-powered lasers and, oh, I've just gotten a big government grant to see if they can be used to knock out incoming ballistic missiles.
Penny: Wow! Can they?
Leonard: Oh, God no! The money's pretty good. And I use the equipment to make my own Bat Signal.
Penny: Bat Signal? What are you, some kind of nerd?
Leonard: Not "some kind of nerd." I am the king of nerds!
Penny: What does that mean?
Leonard: Well, it means if anyone displeases me, I don't help them set up their printer.
Penny: [laughs] You are so funny!
Leonard: [grins] Good! Remember that when I take my shirt off.
He pranks them by using CGI to fake owning an interdimensional portal in a storage cupboard, pretends to be attacked by a tentacled monster, then sneaks up behind them while they're watching a CCTV recording of this on a laptop and throwing said monster puppet at them.
Made even more awesome that Sheldon correctly surmised that the two would actually believe he could pull off the "wormhole generator" he was discussing at the beginning of the episode. Basically, in order for them to believe the CGI thing, they would have to think Sheldon might actually be capable of creating a device that teleports people to other universes! That they did shows how much stock they put in his skills.
Another where he points out it's more helpful for girls to hear from actual women scientists, than from bumbling male scientists about the need for women in the field
Leonard pointing out to Sheldon about the flaws in his "People should help themselves" philosophy (the man that needed a ride from Leonard) and that Star Trek wasn't a gender-blind society due to "the black lady answering the space phone".
Sheldon figuring out the riddle in the comic store first, despite being the last one to arrive and read it. To make clear the scale of this, he figured out the correct answer in ten seconds flat, getting it long before every one else, even Amy. Once again, it's nice to see him showing, that yes, he really is that smart. Compounded when he reads the map coordinates for a few moments, says "got it", and then actually GETS TO USE the bowling ball he had brought along.
In "The Romance Resonance", Howard plans out an event to celebrate the anniversary of his and Bernadette's first date, recruiting everyone to help out with an elaborate musical number he wrote himself. When their plans went sideways because Bernadette was quarantined over a mishap at work (exposure to a raccoon virus), he didn't miss a beat and they migrated over to the hospital, with him singing to her playing a keyboard and the rest providing back-up as she watched and listened through a window. The song ends up being awesome, heartwarming, and hilarious all at the same time.
Regardless of how cruel he was, Sheldon's plan to teach Leonard a lesson in what its like to have OCD was awesome. He managed to manipulate his best friend into torturing himself and drove him to brink of the edge, all while barely lifting a finger. For a guy whose villainous roles are generally somewhere between a petty prankster and Egomaniac control freak, watching him play a Magnificent Bastard was awesome, and finally proved Leonard was right when he claimed he was just one "Lab Accident away from becoming a supervillain."
Leonard outsmarting Sheldon and forcing him to admit that change is good by pointing out that the only reason Sheldon has his spot, which he loves, is because Leonard bought the couch and changed the apartment. Sheldon had no come back for that.
Sheldon also gets one at the end of the same episode by managing to snatch victory from the jaws of defeat. After they've already bought the table and are sitting around it about to eat (except him and Amy, who are still in their regular places), he manages to successfully get them to all come back, simply by playing on the girls' sympathy and subtly guilt tripping them by reminiscing over happy memories that they will never have again.
Howard proves, finally proves, that he's just as smart as any one of the guys despite not having a doctorate.
Sheldon also gets one for his response to Howard's challenge that he doesn't know anything about engineering. When the dynamic is reversed, he easily manages to answer Howards questions to him, proving that yes he really is that smart. The guy maybe a snobbish Jerkass, but he does live up to his own standards.