When he was in Canada with Jon, somebody recognized him just from hearing him say "D'oh, you missed!" to Jon.
Whenever he gives voices to characters, usually giving them strange accents that doesn't even match the respective characters. Old people are also funny.
He always notices when his voice cracks, and makes fun of his own voice-cracking.
In his four-year anniversary video, referring to the bonus episodes of his let's plays that he has been known to put off for long periods of time:
Chugga: I've always been a horrible, horrible human being when it comes to updating my bonus features, 'cause usually during a game, I'm always super-dedicated...and then when it comes to the bonus features, I'm like "I'll do 'em later, mommy..." (Beat) Apparently I havefour hundred and ten thousand mommies. (Beat) I'M SPECIAL!
On Twitter, he mentioned how his friends made him a "really girly cake" for his birthday, and how the symbol on it apparently suits him though he doesn't see why. This is said cake.