Angst? What Angst?: Ted doesn't find the news of his dad's death to be alarming at first, deciding to carry on his life as if nothing happened. He spends the rest of the episode going through the five stages of grief as reality hits him like a brick wall.
Badass Decay: Thing do not go very well for the Law after his defeat at the hands of Brian, as well as being convicted of using an aimbot. He basically goes from the most famous gamer in the world to a unmotivated loser.
Even when he's finally vindicated, he's essentially treated as a Butt Monkey for the rest of the series. Even in the final battle to decide the school's fate, Law doesn't really get anything done other than bicker with the new Law.
Big Lipped Alligator Moment: At the beginning of the very first episode, Brian is attacked and mugged by a couple of RTS players, who jump on a tandem bicycle and fly away on magical rainbow sparkles.
In season 2 episode 5, there's a moment right before Shotbot's Heroic Sacrifice where he can be seen speaking something in Japanese to Law against a flowery background.
Brian's "nightmare" in episode 3 of season 1.
Bizarro Episode: Episode 8 of Season 1. A common complaint is the way-too-fast-pacing. None of this is helped by the fact that the episode doesn't transition smoothly (How does Brian get expelled and suddenly own someone else's arcade in one day?) and as a result, some viewers may try to spend the entire episode trying to figure out if it was a Dream Sequence.
Broken Base: The show's fan base is fairly divided over season 3's style, heavily amplifying the drama. Some believe that the show works fine as a drama, but others are uncomfortable with the show being so far away from its roots.
Freud Was Right: In season 3 episode 3, when the team convinces Brian that Jenny wanting to invite him over "for dinner" is really a booty call, the scene ends with a close-up shot of a banana that Games had been immaturely toying with...
Ho Yay: At the end of the finale, there's a particularly homoerotic scenario with Law and New Law. The Laws are planning to go somewhere on motorcycle, but it's only single-seated. New Law says he has a small butt, and Law adds to that by saying that he noticed it. New Law then wishes for the situation not to get awkward.
Moral Event Horizon: Freddie bequeathing all of his most valuable belongings to someone he hasn't even met while giving Ted a small, crappy gift in his last will video.
Nightmare Fuel: The scene in the finale where Law goes nigh-insane, taking a Nintendo 64 controller and swinging it around his head when a customer asks to buy a Napalm drink. Brian just so happens to be a bystander and looks on in horror. We don't see the scene's resolution, but it is grimly insinuated that the customer gets killed.
Doesn't help that the scene immediately afterward has Law saying "NO ONE WILL EVER KNOW!", and then having it cut to Brian with a scarred look on his face.
Real-Life Relative: Real life brothers Freddie and Jimmy play a hilarious father-son dynamic.
Episode 9 has a moment too, due to the subtle implication that he didn't get the girl in the end, no matter how much they both like each other. However, that could go either way come Season 2.
Ted, somewhat. His father, Freddie Wong, seems to absolutely detest him, despite Ted having nothing but respect for the man. It gets shattered when Freddie dies in season 3, even though it took Ted the whole episode for the realization to dawn upon him.
Season 2 continues to pile misfortune onto Brian. Not only does he have to deal with The Law being his new roommate, but due to the The Law's aimbot scandal, the scholarship Brian used to enroll in VGHS has been discontinued. He now owes over $100k to the school, and is forced to work as a janitor in order to pay off his debt, despite running an entire arcade last season.