Buzz and the toys driving the Pizza Planet truck to rescue Woody.
Buzz and co. blinding the Prospector with cameras to save Woody, then proceding to dump ol' Pete in the backpack of an "artist".
The battle between the other Buzz and Zurg. To the audience and the other toys, they look like idiots. To the two of them, it's a battle between a Space Ranger and his Arch-EnemyThe Emperor, with laser shots and ion blasts filling the air.
This one is subtle: Other Buzz works his way rung-by-rung up the elevator shaft, so to speak, dragging the other toys below him. He visibly struggles with each inch when he see him later, then we see he'd gotten about halfway between the 22nd and 23rd floor. Let's go over that again... he'd scaled the elevator shaft, from the ground floor, all the way up to in-between the aforementioned floors. And this was while burdened with the other toys' weight. That deserves some props for that level of strength and endurance.
Actually, he was at the 13th/14th floor when we got back to him, further accentuated by Buzz's line of being "halfway there." Doesn't make this less awesome, though.
"HEY! NO ONE DOES THAT TO MY FRIEND!"
Buzz reuniting with the group and proving beyond a shadow of a doubt he's the Buzz they all know and love by silently lifting the other Buzz's helmet up causing him to gasp for air (just like Buzz himself did in the first one) and then lifting up his foot with Andy's name on it.
A meta one for the animators. In spite of several months of serious Executive Meddling, Pixar managed to complete the film in less than a year, persuade their executives to release it in cinemas again. This allowed them greater independence, and made them one of the animation giants they are now.