Steins;Gate/Heartwarming

Anime

 * Mayuri's excitement upon discovering that there is another girl joining Future Gadget Lab. First thing she does when Kurisu introduces herself as the newest Lab Member? The former runs up to her and gives her a great big hug.
 * In Episode 9, Kurisu bursts into tears after an argument she had with someone over the phone. As she sobs into Mayuri's Oopa cushion, Okabe tells her that he values her as a friend, and she can tell him anything. Now granted, he only said that to bait a reaction out of her, but even still, she brings this up later on as something meaningful to her, and not just a throwaway line.
 * Many interactions between Okabe and Kurisu in the second half of the TV series, particularly:
 * In episode 14, when Kurisu makes a Mad Scientist impersonation (complete with Insane Laugh) in order to cheer Okabe up.
 * In episode 22, the whole scene where Okabe.
 * In episode 23, when Okabe meets Kurisu again . Doubles as Tear Jerker.
 * The final line in episode 25, an obvious Call Back to episode 22

Film

 * Okabe invites the gang over for a rooftop barbeque. His reason? He heard "a certain wayward assistant" was back in town.
 * Though she was drunk at the time, it was lovely to see a softer side of Kurisu, as she starts flirting with Okabe, rubbing his cheeks, and cuddling him.