Usually there's one, may be two, and rarely three good jokes in any Simpson's episode. Season17 didn't have a single good joke.
This is the first time in over 20 years that I've watched an episode of The Simpsons and thought "Wow, that was a good story." The jokes are meh, but the Story is great. Mainly because for once everyone isn't being a completely self-serving rump, and show some actual care for someone's suffering instead of just making crass and vulgar fun at that character's expense.
Ultimately, this is the perfect note to stop watching The Simpsons with. I doubt they'll ever top it, and frankly, the show has way outlived its ability to be truly entertaining above the level of, say, Three Stooges humor.