When Pewds is playing Sonic.exe and Robotnik's level cuts to static, he keeps repeating "Don't come out of the screen, Sonic...". When he finally does come out of the screen (The "I am God" picture), Pewdie doesn't so much as freak out, just giving the picture a solid look and then going: "Okay, I mean, Sonic, you're not that beautiful. Let's be honest." For a guy who has been notoriously known screaming at these sorts of things, it's awesome for him to learn from his past and adapt accordingly.
During his Dark Souls playthrough he managed to beat the Iron Golem without Tarkus (for context, this boss is considered ridiculously hard, if not nigh-impossible, to beat unless you get an ally spirit named Tarkus to help you). Even Pewds is surprised and he spends the next minute celebrating.
For bonus points, early on he summons other players to help in a boss fight, despite being unaware of exactly how the summoning mechanic works. When he realizes that the other players did most of the work for him, he deems summoning to be a cheap, cheaty tactic and goes solo from then on.
In one of his Outlast videos, there's a scenario in which Pewdie accidentally comes out of his hiding locker. He quickly hides in the one next to it. Three guesses which locker the enemy checks.
In one of his Pewds Does Everything videos, he smacks his butt with a banana, and when he notices the camera he awkwardly throws the banana backwards. It then lands perfectly on the table behind him.
In his Goat Simulator video, he makes his goat collapse on the ground just as a car drifts by and just barely misses hitting him.
In one of his Trouble in Terrorist Town videos, he jumps off of a building and ends up landing on CaptainSparklez. The round ends, as CaptainSparklez was the traitor the entire time and Pewds had killed the traitor without any intention.
Pewds recently started his Dark Souls 2 LP and has been having a great deal of trouble with it. It wasn't until someone pointed out that he was in the ChampionsCovenant that his problems made sense. After looking up what it does and realizing it makes the game about twice as hard Pewds decided to stick with it.
In his latest video he fought the Iron King. For those not in the know this is That One Boss for a lot of people. Pewds defeated it, while still part of the Champions Covenant and while using only melee (the hardest method of fighting it) apparently on the first try.
In the Squish Oculus Rift video, while the walls are closing in Pewdie begs to the game that he'll do anything to get out. Suddenly, the walls stop just as he's saying it. When Pewdie changes his mind, the walls actually continue closing in.
He wasn't doing this on purpose. There's actually a disclaimer that says he didn't even know what to expect.
The quick kiss Pewdie and Marzia share in part 6 of his Fahrenheit LP. It's fast, but it's still there.
His response to the whole Retsupurae controversy and his controversial comment, pretty much destroying the general image that some of his Hate Dumb like to portray him as; extra points for not doing it with sarcasm or ranting (even considering his previous comments an Old Shame). Regardless of what side you fall on regarding PewDiePie's entertainment value, the fact he can be mature enough to do this kind of response despite what his Hate Dumb likes to paint him as is awesome.
Also a Crowning Moment of Heartwarming as he yet again thanks his fans for helping him be in the position he is in.
Even better is that Retsupurae, when discussing him shortly after the Adults React video, admitted to doubting that anything would ever make him change his ways, as long as he was still making money.
Pewds is the #1 most subscribed channel on Youtube (not counting Youtube's channels) and as of now has 27 million bros. That's one hell of an accomplishment.
Pewds being able to raise $450,000 ($200,000 more than his goal) for his Charity: Water campaign to help the less-fortunate get clean drinking water. Also doubles as a CMOH.