What is good English pronunciation?

There are three levels of English pronunciation:

Level 3 will be called good pronunciation. Notice that good pronunciation is not "perfect American or British accent". You don't have to sound like the Queen of England or the President of the United States of America.

Why not? Because there are many regional kinds of English. In England, people from Newcastle speak English differently from people in London. In America, people from New York City, California, and Texas each have their own pronunciation. So it is no problem if you have your own accent.

But your accent must be close to the standards (American and British English). What does it mean? Turn on your TV and watch channels like CNN International, NBC, EuroNews, BBC, or Sky News. You will hear many different people (news anchors, reporters, etc.) from Germany, France, and other non-English-speaking countries. They all have good accents — easy to understand and pleasant.

The rule is: If you are close to the standard, you can always communicate, and your English will be pleasant. If you are far from the standard, sometimes you won't communicate successfully.