In the purest sense of the word "cathartic," absolutely 86. There's nothing - literally nothing, in any media - that's ever touched me the way the last episode of that series does.
Honorable mentions:
In a similar sense, Akudama Drive. It's especially rewarding because with the vividly over-the-top beginning, it doesn't feel like that's the way it's headed, but it is.
In a milder sense, Honey Lemon Soda. There's just something about that series - to me, it's far better and more satisfying than any of its better-known rivals.
In a similar vein to that, Words Bubble Up Like Soda Pop, which as a bonus is visually stunning too.
In a somewhat different sense, the original OVA of Little Witch Academia. It just sweeps me up from the very first frame and doesn't let go until the last.
And in the more traditional sense, say what you might about the series as a whole, but Sword Art Online S01E03 - The Red-nosed Reindeer - is beautifully touching, as is the entire Mother's Rosario arc.