Quarter 57... just Quarter 57. If Kuroko and Kagami making up and vowing to get stronger together wasn't enough for you, then there's Kuroko's little speech.
Kuroko: "I'm glad I came to Seirin. All the seniors are nice. My classmates are who try hard together are also nice. You believed in me. I'm no longer the Kuroko Tetsuya of Teikou. I'm Kuroko Tetsuya of Seirin High School."
The end of the Touou vs. Kaijou match. Kasamatsu helps an ailing Kise to the player lineup and comforts him by vowing to make all the opponents pay during the Winter Cup. The fact the Kise is sobbing his heart out after his loss makes the moment even sweeter.
Kasamatsu's Rousing Speech to his team in the aftermath of Touou vs. Kaijou game.
Kasamatsu: "Buck up everybody! You've tried your best! We're among the best eight teams in the entire nation! Go back with pride!"
Quarter 120. Kuroko has hit rock bottom and is crying tears of despair when suddenly...
Kagami: "It's not useless, idiot."
During the Yousen match Kagami asks Kuroko to throw away the ring Himuro gave him, because the current relationship he has with the team is much more important than clinging onto a past relationship with him. Awwwww...
The follow-up after the match is just as sweet, when Kuroko reveals that he's actually kept the ring because he cares about Kagami and believes he can still mend his past relationship with Himuro. Double awwwwww.
Quarter 205: The way Aomine took to Kuroko and decided to befriend and train with him. Then later in the same chapter, telling Kuroko that there's "no such thing as a useless player on a team" when Kuroko wanted to quit after being told by the coach that the basketball club was not for him. You can see why, despite Aomine becoming a Jerkass later, Kuroko still wants to help Aomine enjoy playing basketball again.
Quarter 102: Teppei covering the inside in the game against Kirisaki Daiichi so the other team focus their attacks on him and no one else gets hurt. Not to mention his speech after getting a really bad elbow hit to the head.
Teppei:(in a flashback) "I've been thinking what can I do for Seirin when I get back. If they continue fighting this way, their hearts might get fragile from overwhelming powers like Teikou. They might get threatened by dangerous opponents like Hanamiya."
Teppei: "That's why I decided. If their hearts get fragile, I'll become their support. If they're threatened, I'll become their shield. I'll sacrifice myself any day to protect everyone. That's why I came back!"
Quarter 177: Things aren't looking good for Shutoku in their match against Rakuzan, Miyaji is unable to stop Hayama from scoring, and Mibuchi tells Midorima that aside from him, every other Shutoku player is a hindrance. Midorima then proceeds to block Hayama from scoring when he gets past Miyaji again, bypasses a double-team attempt with the help of a surprise screen from Kimura, and prepares to take a shot. Nebuya tries to screen him, only for Midorima to instead pass the ball to Miyaji, who scores immediately.
Midorima: "There's not a single player on this team who's a hindrance."
Pretty much any time Seirin wins. Espicially towards the end. Espicially when they beat Rakuzan.