In Germany, it is the Test.
- It is thought to be the very best by most experts/critics.
- In my condition's school system, it's also on the necessary reading listing when it comes to Abitur (the certification you'll want to learn at a German institution) exam.
- It's also the only fragment that is the many readable, I think.
- The test has also been in Le Monde's number, therefore I guess you can state that in France, The test is deemed their best guide.
Yourself, I also just like the test the most.
It's extremely well written (Kafka was, although a Czech national, a master of the German language) and it is so cryptic that it can virtually interpreted in any imaginable way. The angle is however, that you never get the effect he was just writing out stuff that is supposed to confuse your reader. While every thing on it is really so complicated and cryptic, you will have the impression that there surely is a conclusion for almost any facet of the book.
Another quality I admire is his humour: It is a tremendously simple and unobvious humour. He's essentially constantly mocking the protagonist, Josef K., during the period of the book.
Globally (especially the US) it may be the Metamorphosis, this is certainly at least the impression I get.