Everyone who is a fan of Community has a favorite episode or two, and it might be fair to say that those episodes often come from the first three seasons. All the original characters were present in nearly all the episodes, the story lines were funny and original enough that they deserved a re-watch.
It's somewhere in the middle of the fourth season that interest might get lost and that's understandable. Something changed with the show, and while the three later seasons weren't bad, they did lack some of the charm that came with the original three.
The fifth season sits in a strange limbo where it was in between behind-the-scenes changes. The quality of the fifth season belongs with the greats like seasons one, two and three. Between the firing a showrunner and the switching of a network entirely, the fifth season rests in an awkward twilight zone where it's overlooked with its classic episodes thanks to coming off the heels of a relatively bad fourth season.
As sad as it is to admit, the fourth season ruined it for the fifth but fans shouldn't accept that. The fifth season of Community had some amazingly written storylines and character arcs and deserves a lot more praise than what it was given.