I'm biased in that for me "ZULU" was one of the best. It made Michael Caine a star. Also because of 'the local welsh connection', it is commemorated back home in Ferndale, Rhondda. Did you know that the cattle used in the film was given to the Zulus after the film was finished so that Stanley Baker and the management team could get round the apartheid laws regarding wages for the Zulus - FACT!
There were many epic films that I liked and the list is endless so I won't bore you all with them.