In elementary school I'm fairly sure there wasn't a single book we were told we had to read, but often we had to read a book or a number of books and then write reports on them and all. In HS there were a number of books that we did have to read, but not many compared to what seems to be the norm in US schools. We often just read fragments of books, rather than the entire works, which has both advantages and disadvantages, really... it does allow you to cover a lot more ground and all.

As to which books should be obligatory, it obviously depends on the country; I'd consider putting To Kill a Mockingbird on the list for the US, but for other countries that book would obviously have far lower priority, whereas for instance in Germany a book like Der Vorleser (The Reader - the one turned into a movie last year) might be considered. 1984 on the other hand might be interesting everywhere (at least in the Western world).