Courtesy of the final episode of Season 1. Ai attempts to expose Hajime as a hypocrite to his daughter Tsugumi by summoning a manifestation of his wife's car accident, to which we saw him responding in flashback "it's not my fault". This accident happened, mind you, after he rejected her attempt at reconcilement and she ran to her car crying. But when he sees the scene, he bursts into tears, emotionally crushed at the reminder that his wife died because he wouldn't forgive her. So Tsugumi decides to stand by her dad and rejects Ai's offer to send him to Hell.
The (VERY) few episodes where someone doesn't end up in hell tend to have one of these as well.
The episodes where Ai's companions show they care about her.
A brief but touching moment an episode of season one: a young circus performer is mistreated and locked up in an old warehouse, while her twin sister is spoiled rotten. Upon finding the abused girl (who is staring into space and singing quietly to herself), Ai silently lays a hand on the girl's cheek.
Ai seems to sympathize with people who have been betrayed by those they cared about.
A brief moment in Episode 25 of Mitsuganae: At one point during Yuzuki's backstory, we see a younger Akie come across Yuzuki while she's sitting by herself by a riverbank, and she gives Yuzuki a piece of candy to try to cheer her up. Clearly this moment stuck with Yuzuki, since we had actually seen a brief glimpse of it in episode 13, flashing through Yuzuki's mind to warn her that Akie was in danger.