While I love Elizabeth Taylor as Cleopatra, my personal favorite actress to play the role is Claudette Colbert. There was just something extra special about her performance – as much in the way she carried herself as anything.
Cleopatra (1934) was directed by the extraordinary Cecil B. DeMille and starred Warren William as Julius Caesar, Henry Wilcoxon as Marc Anthony, and Claudette Colbert (of course) as an especially regal and radiant Cleopatra.
You can find the wonderful 1934 Cleopatra on dvd (Amazon link).