There are many publications and organizations that hold Bad Writing Contests, and they print many examples of atrocious writing. Below are some of the bad writing contests I think you can look up on Google. I think the Bulwer-Lytton Fiction
Contest is the oldest and most prestigious.
Bulwer-Lytton Fiction Contest, Weird California, Weird Oshkosh, Weird San Jose, Bad Writer, Weird Wisconsin, Worst Writer, Weird News
The excerpt below is from Weird News, which you can access on Google.
Sue Fondrie of Oshkosh, Wis., won the 2011 Bulwer-Lytton Fiction Contest for her sentence comparing forgotten memories to dead sparrows, said San Jose State University Prof. Scott Rice. The contestant asks writers to submit the worst possible opening sentences to imaginary novels.
Fondrie wrote: "Cheryl's mind turned like the vanes of a wind-powered turbine, chopping her sparrow-like thoughts into bloody pieces that fell onto a growing pile of forgotten memories."
This bad writing was intentional, but much of the bad writing that wins contests is unintentionally bad. If you just google "Bad Writing Contests" you will easily find dozens of examples of truly horrible prose.
As far as good prose is concerned, there are thousands of possible examples from the world's literature. E. B. White was considered an outstanding American prose writer. Ernest Hemingway was an excellent prose writer. Bertrand Russell, the British philosopher, wrote beautiful prose. Dr. Samuel Johnson wrote ponderous prose, but he said:
Whoever wishes to attain an English style, familiar but not coarse, and elegant but not ostentatious, must give his days and nights to the volumes of Addison.
That is Joseph Addison (1672-1719), best known as one of the two authors of The Spectator.
Incidentally, the little book titled The Elements of Style, written by William Strunk and E. B. White, is full of examples of good and bad prose. The last chapter is of great value to aspiring writers. It was written by E. B. White when he reissued the book originally written many years earlier by his English professor William Strunk. (I think it was at Cornell.)
Henry James wrote flawless prose in the grand manner. There is no better writer of English prose than "The Master," Henry James. Marcel Proust wrote incredibly good prose in French, and it still reads very well as translated into English by Moncrieff. William Faulkner's prose is often hard to follow, but it is well worth the effort.
For excellent prose in the American vernacular, I think Dashiell Hammett's The Maltese Falcon is hard to beat. Here is a very brief example from the chapter in which Casper Gutman tosses an envelope containing ten one-thousand-dollar bills to Sam Spade.
The envelope, though not bulky, was heavy enough to fly true.
Dashiell Hammett must have been a perfectionist. The Maltese Falcon is full of admirable exposition, description, and especially dialogue.
I could go on and on about good writers and good prose--but I won't.