Episode twenty-five of Death Note really knocks it out of the park; it's so strange and stylish and interesting. Just brilliantly directed, which isn't something I often find myself thinking about an episode of an animated show. It may not be the first or the last episode of Death Note, but I think it's the most important episode of Death Note, and it's incredibly done.
Although the anime is a direct adaptation of the manga, often almost shot-for-shot, the rooftop conversation in the rain and the foot massage afterwards were added for the anime. I think they're both very strong additions. I just love this strange intimacy between two characters when one of them is in the process of murdering the other.
It's very striking that, after Light's conflicted acceptance of L's weirdly intimate foot massage offer, Light reciprocates the weird intimacy by taking up a towel and drying L's face. I think it's the only time in the entire series we see Light reaching out to another person in a way that doesn't feel calculated. He's killed L already; he's laid the groundwork, his plan is in motion. And, with L about to stop breathing, Light can afford to have this strangely human moment with him.
I'd love to see more of Light missing L or being haunted by him after the fact. We do get some good glimpses of his complicated feelings once L's gone, though! So easy... it's no fun without Ryuzaki, he finds himself thinking. It reminds me of his 'If you'd been smarter, this could've been interesting' when he killed Lind L Tailor, not realising how interesting it was about to get.
Light is a person who craves challenge, and I think it really empties him out to lose the challenge that L brought into his life. He's been a dark character for a long time, but he feels darker and more ruthless once L is gone, and I think he's taking less pleasure in his role as Kira. Poor Light (who is a murderer), deprived of his main source of intellectual stimulation (on account of having murdered him).