Well, I would think the feature length TV movies would be the ones toward the bottom of the list, as they're generally less meaningful productions. Of those three, I actually like VXM the most. Yes, some of the gags were quickly dated because they're a bit too tied to the immediate moment, but it's the one film that feels the most like a Muppet Show episode to me in being a backstage look. And the Moulin Scrooge number is brilliant.
Kermit's Swamp Years isn't bad, it's just kinda forgettable. It's more just sweet with not enough spice, and the Muppets need spice. Kermit may always have good intentions, but he doesn't always act like a perfect person.
As for MWOZ, well, it just doesn't quite work. Let's be honest, the Muppet storybook stuff is a mixed bag. MCC and MTI are great. MWOZ...is not. And, frankly, the fact that it was the first major project after Disney bought them tells you a lot about Disney's corporate obsession with Wizard Of Oz. Walt himself wanted to make an adaptation of Wizard of Oz as his second animated feature after Snow White, only for the rights to already have been acquired by MGM, which made the classic film (it's now owned by Warner Bros. because of ownership deals from the 80s). Ever since it seems the company has a permanent culture of trying to avenge that loss, repeatedly making sequels, prequels, and remakes that all fail to live up to the classic. That it tainted the Muppets is just part of the fallout there.