Each of the Star Trek TNG, DS9, Voyger, and Enterprise.

The X-Files got mcuh better up until it fell apart. And outisde some of the last season, Fringe got better along the away.

Friday Night Lights increased in quality after Season 2.

ST: DS9
Angel

really liked seasons 3-5, which were the Directv seasons. I think the show definitely got better in it's run.

I haven't caught any of the new/final season yet, but I'll say BOARDWALK EMPIRE. I think it's gotten progressively more entertaining with each new season.

I agree!

Fringe
Parks and Rec
Agents of Shield
Person of Interest

QL is one of my favorite shows but the finale is pretty 'meh' outside of the final 5 or so minutes. The final bit with Al and the whole not going home gets me every time but the first 40 minutes are pretty average.

That's because it wasn't supposed to be the finale. It was written to work as something of a finale if the show wasn't renewed, but not to be a complete ending.

They had a couple of ideas for the next season: One was trying to find Sam who was now leaping on his own, and the other was shifting the show so it could include the future as possible destinations. NBC axed the show, so we got the text on screen instead.

As a huge fan, I'm aware it wasn't supposed to be the series finale. I'm with Xiroteus in wondering what johnnysd finds so great about it.

It's a fine episode I liked revisiting Jimmy but overall it's just another episode. Makes you wonder if it did continue if they could have pulled off a great series finale or if it would have just petered out like Lost, X-files, HIMYM or so many others.

Still want to see that QL reboot with Sam's daughter.

Homicide: Life on the Street

Angel was a chore to get through in Season 1.

Fringe while good became great at the end of Season 1 going into 2.

I'll disagree, Season 1 was excellent, then Season 2 was pretty terrible (and took place during the writer's strike) and then season 3 and on built up. But it started off pretty strong, I thought.

Agents of Shield has probably the biggest turnaround in one season that I've ever seen, and I'm still not convinced that it was the plan all along and not a course correction, but maybe we'll never know. However, it's only on it's second season. I'd think most long running shows that are popular enough to be renewed will jump the shark at some point, so that limits the discussion to either spectacular shows (like Breaking Bad) or short lived shows. For instance, the Office season 1 was basically terrible, I had to force my wife to sit through it to get to season 2, but it went on so long that nobody would say it ended on a high.

Parks and Rec has been up and down, especially the last couple of years, but the transformation of the cast is pretty remarkable... turning Andy into Homer Simpson really changed his trajectory.

Heroes is like the antithesis of this premise.

I also enjoyed season 1 of FNL and I agree season 2, was terrible and the writer's strike was part of that. There were a couple of storylines in season 2 that were awful to begin with.

So the plan was to make the show terrible for the first half of the season to weed out potential viewers before making the show good?

It's a though question. I can think of shows that started strong and went downhill (Vampire Diaries, Dawson's Creek); or started strong, peaked and went down (Alias around season 2 or Buffy after season //3); or had a strong first season and maintained a good degree of quality (Everwood, Felicity, Chuck). However, I struggle to think of shows that started wobbly and continued to improve. Maybe something like Stargate SG-1?

Problem is most shows that are around long enough to improve, also are around long enough to go downhill and outstay their welcome.

These are the ones that kept getting better and/or smarter and/or dumber as the seasons grew. Mostly talking longer running shows.

I contend that: Seinfeld, Cheers and Brooklyn Nine-Nine got better and better through its runs. Especially Seinfeld and B99 might not be over yet. But two old, one new. Seinfeld built imo as the years went by. It had some hiccups, but for most part, continued to be funny.

Cheers, with all the additions after the Coach years were brilliant and that show grew, not just funny, but also bits of poignancy. B99 just funnier and funnier and more assured through years.

Seinfeld dipped a little in the last 2 seasons when Larry David left and the storylines got more and more out there. Don't get me wrong I still love those episodes but Season 4-6 was the peak.

I can't think of a single sitcom that continually got better until they went off the air. Some managed to maintain the same high level of quality that they established right until the very end. But I can't think of a sitcom that was at its best when it ended.

Parks and Rec

The usual trajectory for a great sitcom is the first 2 seasons kind of finds its footing and develops the characters. The middle seasons are usually the best as the show hits its peak between, and then usually starts to dip in the last 2-3 seasons if they hang on too long as the characters start becoming a caricature.

Cheers, All in Family, King of Queens, Everybody Loves Raymond, Three's Company, Happy Days are a just a few examples who had this trajectory. I can't think of a single sitcom that didn't drop in quality in its last 2 seasons.

Animated shows are kind of in a different category, but the first two seasons of The Simpsons aren't really that good compared to seasons 3-9. Also I don't think the first season of American Dad is that good compared to the rest of the show.

This is a good one. First season was really rough. Then got progressively better and went out relatively on top.

Agree with this one.

Seinfeld is my all time favorite sitcom, but it didn't get continually better through to the end. As much as I like the absurdity of the latter seasons, the show was at its best before that.

I think Sunny got progressively better as well. Started off great...had a lull on the middle...but has been pretty consistent the last few.

The Middle. Not every episode in some of the later seasons was a home run but talk about a show that got better as it went along. The final stretch of The Middle episodes is as good as or pretty close to some of the classic episodes from earlier seasons.