Answer
**Answer:** Film. **Explanation:** George Marshall had a more successful and prolific career in film directing compared to television. He directed over 100 feature films, many of which were critically acclaimed and commercially successful. In contrast, he only directed a handful of television episodes and specials. His notable successes in film include "Destry Rides Again" (1939), "The Forest Rangers" (1942), and "How the West Was Won" (1962).