These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Moment Of Awesome: Yuuko(!!!), of all people, gets one in Episode 16 when after confirming (with the Professor's help) that Nano is a robot, she tells her that "I know that you aren't a robot. Nano-chan is just Nano-chan." Not only does Yuuko make it clear that she doesn't mind that Nano is a robot and considers her a friend, but it also helps Nano to accept herself. A CMOH and a CMOA in a single strike: well done, Yuuko!
And then Sakamoto accidentally talks in front of her, telling her goodnight. "Meh, whatever."
Friendly Fandoms: The relationship between this show's fandom and Daily Lives of High School Boys's fandom, both due to them being similar in name and due to them sharing a genre. Both will argue about which show they think is better, but the arguments never get heated, and both fandoms seem to respect each other and their respective shows. If someone has only seen one show and not the other, fans will often urge them to watch the other as well.
The elevator scene in episode 8. You can't help but laugh along with the girls, but be creeped out as well. The fact that part of what they laugh at is the fact that Mai appears to have died doesn't help, either.
The elevator scene is incredibly, incredibly surreal. It almost seems to be a mockup of David Lynch-style surreal horror (see Rabbits), what with the disjointed dialogue and strange, atonal soundtrack. The part where they start going into hysterics is the least creepy thing about it.
Nakamura-sensei's leitmotif owes a bit to the James Bond theme.
Tear Jerker: In the "Small thoughts" segment of Episode 10, a teacher is talking about how people respond to either praise or punishments. A girl at the distance thinks: "I react to praise... but I never am..."
The scene in Episode 13 where :the Professor allows Nano to go to school is more of a Heartwarming moment, but for all the problems Nano deals with, a lot of viewers feel tears welling up.