I liked this one. I daresay it's the best Simpsons
episode to come along in many years. It was actually a story driven by the characters rather than by gags and zany situations, and it had a sincerity and sensitivity I haven't seen in the show for a long time (although it was present in the movie). The interspersing of the present day with two flashback periods was interesting, and the parallels were good and often quite funny (I particularly liked Bart and Lisa acting like a married couple on a drive). It was neat to see how Homer met Ned, and fascinating that he liked Ned at first -- though we also got to see the foundations of Homer's hatred for Flanders, and it actually made sense rather than just being some random goofy occurrence. (I meant to check the credits to see if that was Maggie Roswell returning as Maude, but I missed it. Anyone know?)
Of course, it wasn't all character-driven humor, but the slapstick was actually good. The final sequence with Homer and Marge on the tree had me laughing out loud progressively harder as the scene went on, and that hasn't happened with this show for a long damn time.
And one nice detail -- they actually got Maurice LaMarche to play Toucan Sam in his 3-second cameo!
So far this season has been unimpressive, but this episode was the best the show has been in ages. Hopefully it's the start of a trend.