https://www.cracked.com/article_26319_6-tv-finales-you-forgot-were-totally-crazy.html

How I Met Your Mother, Full House, Castle and Lois & Clark had endings that were infamously frustrating.

Seinfeld. One of my favorite shows and worst endings, IMO. It had promise, but was 30 minutes longer than it needed to be. NBC re-green lighting their pilot never made sense, which is what got them in to the final situation. They could have either had their plane crash, and then had the cast and many well-loved one-off people come and talk about how they were horrible shallow people while the main characters watched and made commentary, or they could have had them get arrested and get sentenced to jail as the plot went, but instead of dragging in person after person to slam them as people, they just could have pronounced them horrible people and ended with them going to jail. What they did was overkill. To make matters even worse, right before the finale they aired a retrospective that showed all of the famous one-off scenes, so we had just seen a lot of that stuff right before. To me it was just dumbed down and phoned in for a once smart and witty show.

I just saw the finale of Alice for the first time since the show aired, and that was also head scratching. A few eps before, Alice was considering going on the road with a singer, but the finale starts with Mel selling the diner out of the blue, and everyone scattering to the wind (Jolene opening up a beauty parlor was particularly weird to me). There was no real lead-up to it, and it was just odd.

As a old school Degrassi nut, I liked "School's Out!" - the finale movie - but didn't care for that they tried to cram every teen angst cliché in to one package - something the show never really did in it's original run, and was something I liked about it (that they didn't cram the eps with all kinds of cliché teen stuff - something the Next Gen shows eventually fell victim to). One thing it DID do well is that it showed that people grow up and apart, and that things truly are never the same again once you pass that point in your life. You can't really ever "go home" again.

Quantum Leap had possibly the worst ending ever. They never filmed a final episode, and just did a black screen that said Dr. Beckett never made it home. I loved that show, and was extremely disappointed.