Seinfeld, a sitcom that ran from 1990-1998 is often described as "A show about nothing". But it wasn't really a show about nothing; it had characters and a plot. Nevertheless, unlike the usual sitcom, it didn't have a distinguishing mark to set itself apart from rest of the pool of television comedies. Cheers was about a bar. MASH was about a war. Seinfeld was just about some friends and their daily lives.
The show was set in New York City, and yet unlikely coincidences occurred nearly every day. In a city with the size and population of New York, it's obvious that unplanned meetings and relations aren’t going to happen often (if ever). In Seinfeld however, they did. Because of this, Seinfeld remained a comedy. These improbable events balanced off the realistic personalities of the main characters and the comedic climax of many shows was a intertwining of the minor plots.
The main characters of Seinfeld were bad people. They weren't bad people because they robbed banks. They weren't bad people because they murdered children. They were bad people because they were all amoral and self-centered. But we loved them. Because really, we're all amoral and self-centered too. Don't try to deny it. Don’t.
Unsurprisingly, many of the characters were based on real life people. Idiosyncratic characters like Kramer just can’t be created by a writer.
The big four:
Jerry Seinfeld (Jerry Seinfeld)
The star of Seinfeld is Seinfeld (played by Seinfeld). He plays a professional comedian, and his observational humor often slips into the show. He's gone through innumerable girlfriends, and broken up with each one for an inane reason. His only permanent loves seem to be of cereal and Superman.
George Costanza (Jason Alexander)
Jerry’s best friend since High School, George is the least ethical of the bunch. He is a quitter, a scoundrel, and a cheat. He is a short balding man with glasses, and unfortunately for him, the worst luck in the world. We've all got a bit of George in us that pops up once in a while, but unlike us, when George does these ill deeds, he gets caught.
Elaine Benes (Julia Louis-Dreyfus)
Elaine Benes is the lone female in the gang. She once dated Jerry, but they remain platonic friends for most of the series. She's also had her share of significant others, but most of the time she returns to David Puddy. She’s nearly as bad a person as George is, but you wouldn’t guess it.
Cosmo Kramer (Michael Richards)
Perhaps the most amiable character is Kramer. The lanky man with an antigravitational hairstyle accepts his neighbor's Jerry invitation to "make himself at home" and takes it literally. What belongs to Jerry, belongs to Kramer. Kramer is a moocher in the truest sense of the word, but he’s impossible to dislike. He's fun to watch, most everybody's favorite character...but you wouldn't want to know him.
As the show continued over the years, George and Jerry decide to create a television show. A show about nothing. Based on their own lives. They were to create the very show that they were already in. This is definitely my favorite Seinfeld plot line; the self-recurrence was pure genius (although I'm sure the feedback destroyed some of the cheaper TVs watching it)
Seinfeld ended in its prime (as the most popular show on television), which was considered by most to be a very wise move. Although they might have made much more money by dragging the show out, until we all got sick of it, we left the world of Seinfeld on a high note, and it will go down in history like so.
The final episode(s) of Seinfeld had the gang arrested for not helping a man who was being mugged. To popularize the new law, the “Good Samaritan” law (adopted from the French), the prosecution decides that a win is essential, and brings in dozens of character witnesses to testify against Jerry, George, Elaine and Kramer. The characters of Seinfeld finally had to pay for their lack of morals and were sentenced to a year in jail. I found this a very proper end to the series. Plus, it left room for a movie (don't get your hopes up).
Many were let down with the finale. The average Seinfeld viewer is cynical, whether they realize it or not, and I'm sure they'd be much more satisfied if everyone died. And I bet if the Seinfeld characters were watching, they’d be rooting for death too.
You might want to check out the Seinfeld Episode Guide.