...it should have ended.

Dennis the Menace Season 3.
Three’s Company Season 4.
Modern Family Season 4.

MASH

season 7

HAPPY DAYS
season 2

Past:
Family Matters - Season 8
Home Improvement - Season 7
Gunsmoke - Season 18
Happy Days - Season 8
Charlie's Angels - Season 4
A Different World - Season 5
Three's Company - Season 7
227 - Season 4
Hazel - Season 4
Dallas - Season 10
Dynasty - Season 8
Roseanne - Season 7
Saved By The Bell: The New Class - Season 1
Married with Children - either Season 6 or Season 7
Mad TV - either Season 8 or Season 11
American Idol(Original)- Season 7
Two and a Half Men - Season 10
Becker - Season 3

Present:
Hawaii Five O(Revival)- Season 8
Madam Secretary - Season 3
Blue Bloods - Season 6
Criminal Minds - Season 11
Dancing with the Stars - Season 20
NCIS - Season 13
Macgyver(Revival) - Season 1
The Talk - Season 8
The Amazing Race - Season 25
Chicago Med - Season 4

M*A*S*H: Fourth season.

Married with Children, Season 10. Season 11 was atrocious, and Christina Applegate was getting too old and mature looking to play Kelly Bundy.

The Simpsons, Season 8 or 9. It's been so long since I saw the show but I remember right around there the show changing direction and losing its spark.

Obviously, I’m speaking creative-wise and not ratings-wise.

Bewitched - I think it really should have ended after the second season. It was on a downhill slope beginning with season three. There’s just something very special to me about the first two (black and white) seasons that was lost in season three onward. Bewitched then would have joined The Munsters and The Addams Family as a spooky black and white show with only two seasons. I would also be okay with the show going through season five, but once Dick Sargent took over the role of Darrin, I didn’t care for it anymore.

Gimme a Break! - I would end the show with season five… or possibly the first episode of season six, which feels like a series finale. I just don’t like that final season for how different it is from the rest of the show. It just sticks out like a sore thumb. If I had things my way, there wouldn’t be a season six of Gimme a Break!. Then again, if I had things my way, I wouldn’t waste my time eliminating a season from a show. I’d have better things to do, haha.

Family Matters - This show just ran way too long. I’d probably end it with season five being the final season.

Gimme a Break! - I would end the show with season five… or possibly the first episode of season six, which feels like a series finale. I just don’t like that final season for how different it is from the rest of the show. It just sticks out like a sore thumb. If I had things my way, there wouldn’t be a season six of Gimme a Break!. Then again, if I had things my way, I wouldn’t waste my time eliminating a season from a show. I’d have better things to do, haha.

This reminded me of the Drew Carey Show, how it suddenly changed direction in the very last season for no reason at all, ruining the very things that made the show likable in the first season.

Roseanne also ran one season too long.

Two and a Half Men - season 8. This was Charlie Sheen's show.

Diff'rent Strokes - season 6, maybe 7.

Everybody Loves Raymond - season 8. Also, that season had a great finale.

The next two have to do with losing main cast:

Happy Days - season 7

All In The Family - season 8