I'm Egyptian and very interested in English I'm only 16 years and aim to speak English better than Americans.
A very praiseworthy aim! However, you should remember that all native speakers of English speak it perfectly and you cannot improve on perfection. I expect you mean that you are looking to acquire a large vocabulary. There are of course many non-native speakers of English who have vocabularies larger than the average native speaker. You should also remember that language is part of one's experience so there will always be areas of English that are likely to remain closed to you.
I asked a lot of English teachers, native speaker and other famous persons who speak English about the best way to learn English and this is some advices to be good in English:
1- Try to take an English course in American university in your country.
Fine if you want to concentrate on American English.
2- Listen to the radio about 2 hours per day.
Good idea - but rememebr there is not only the Voice of America and the BBC but other English speaking countries that broadcast. e.g. Australia.
3- Try to speak English with anyone in your family or of your friends.
This is good as long as the people you speak with are fairly competent in English - but remember that you are Egypian and you need to speak in your local language as well!
4- Watch American films without looking to the translation.
Don't just watch American films. I would be inclined to read the subtitles - watching the film should be enjoyable as well as helping you with your English. If you have DVD you should watch a few film with the subtitles on and then without and see how much you remember. When you think you are doing well watch a film without the subtitiles and then with. If you missed a lot go back to watching with subtitles first.
5- Make friends through the internet who speak English from USA and UK.
Nothing wrong with that. If you speak to people your own age you will of course learn a lot of non-standard English!
6- Decide if you'll learn American English or British English. (About me I prefer American English because it's simple and easy but Americans speak very quick. About British Englsih I think it's complicated and use difficult words
There is a misconception that there is a big difference between Standard American English and Standard British English. These two varieties of English are about 99.9% the same. Some words are spelled differently - the differences can be set out on a page. There are some differences in every day vocabulary, mainly to do wth food, clothing and household items - again these can be set out on a page. There are some other differences that most American and British speakers do not notice as they are as much matters of style and preference as anything else. If you can read The Times of London you can read The Washington Post. There are of course different accents and you need to decide which one you are going to try and imitate. Unless you have a very acute ear, I suspect you will always sound more Egyptian than either American or British. It all depends on who you think you are likely to be dealing with. Remember that most Europeans learn to speak using what is sometimes termed a Standard Southern English, i.e. a British accent. An American accent has virtually no prestige in the UK. On the other hand many Americans love to hear what they consider a cultivated English accent. Others, however, do not find it so charming. If you expect to meet native English speakers from all over the world you should try and get as much experience as you can of different varieties of English. You should also remember that within the UK there is a great variety in the way people speak. A man from from Glasgow and a man from London will probably have more difficulty understanding each other than either will have in understanding an American TV show.