They did. Sort of. The producers realized very early on that Wonderfalls was the kind of show that early 2000s Fox loved to cancel after a single season. But they also realized that, due to some scheduling quirk, they’d be able to film every episode of the season before the show premiered on TV. So they made it a self-contained story that could be continued if they somehow got renewed. They didn’t, but we got the DVD.
I also love time-travel. *Journeyman *had real potential.
All time best one-season show: Frank’s Place. So good it’s not even on DVD so it lives on as perfection in my mind.
This series supposedly ran for “two” seasons, but they were back-to-back over the winter of 1966-67 and totalled only 29 episodes. I would have loved to have seen it:
I’m going to pick two recent ones (that were both already said but oh well :))
Almost Human. I really was getting into this show. I liked that it wasn’t a terrible future, just a future.
A to Z. Cristin Milioti has charisma to spare and the show was just getting interesting when it was canceled.
I mentioned this in a different thread a short while ago when Elizabeth Peña passed away:
“I Married Dora” had an incredible finale. Knocked me on my can when I first saw it. 13 episodes.
There was another season several years later on Saturday mornings. It wasn’t very good; I knew not to bother in the opening scenes where new actors were in all the roles, and that wasn’t a basis for the plot (“Mom, you look different! I look different!” “Oh, Marshall, don’t be ridiculous. We look just the way we always did.”).
Once a Hero. A great parody of the comic book genre; ran only three episodes. The fourth episode was about an actor who had gotten too well identified with a comic book character he played (shades of Birdman) and had Adam West in the role.
I can’t believe that no one has mentioned, Max Headroom a great sci-fi series from a dystopian future that isn’t too fetched looking at it 30 years later
Hot Pursuit from 1984. Basically it was The Fugitive with a couple on the run.
It actually WAS the basis for the plot. The premise of the series was that it was the Eerie of another universe, and that the weirdness from the first Eerie was leaking in. They actually spoke to the characters from the original series.
This actually ran two seasons, but the second one wasn’t as good as the first, and it’s not on DVD, either. It was on The N, and would have done better on Adult Swim; it’s a cartoon called “O’Grady” and I just found out a few days ago that it’s on You Tube.
Babes, A 1990-91 sitcom about 3 overweight sisters sharing a small NYC apartment. I thought it was funny, and so did a lot of other people. But there weren’t enough of us for a second season.
I think I was the only person who enjoyed recent sit-com Friends With Better Lives. I thought they were quite a likeable bunch.
Day Breakwas one of several ‘what’s the mystery?’ shows that were produced in the wake of Lost’s runaway ratings. I don’t know if any of them went past one season. Day Break certainly didn’t.
Sheldon’s Leonard’s Big Eddie (1975).
My wife and I use this show as the standard we measure all bad TV by. So far, we haven’t found one to surpass its awfulness.
Re Memphis Beat
I coulda managed to enjoy it more if I’d of had a big plate of ribs in front of me…to distract me. 
I’m so glad someone else remembered and enjoyed this show.
“The Famous Teddy Z” Jon Cryer, highly regarded at the time. 20 episodes, 5 of them never aired.
“F/X: The Series”, a syndicated show starring Cameron Daddo as Rollie Tyler. Lasted two seasons but I never got to see the second.
After the success of “Mork & Mindy”, ABC had Fonzie meet an exotic female bodyguard with the goal of giving the bodyguard her own show. “Katmandu” didn’t get past the pilot.
Aw man. Rip off the scab.
The Adventures of Brisco County, Jr. starring Bruce Campbell as a old West lawyer turned bounty hunter as he chases a time travelling uber-bad intent on taking over the science fictiony powers of a set of mysterious orbs from the future.
It was awesome. It debuted the same year as X-Files and Fox decided it would only renew one of them. I still have never watched X-Files just for spite.
Bridget Loves Bernie ran for the 1972-1973 season on CBS.
Occasional Wife ran for the 1966-1967 season on NBC
“He & She” Real life husband and wife Paula Prentiss and Richard Benjamin starred. 26 episodes.