Write SQL query to solve given problem: Which category is the most common?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T.name FROM ( SELECT T2.name, COUNT(T2.name) AS num FROM film_category AS T1 INNER JOIN category AS T2 ON T1.category_id = T2.category_id GROUP BY T2.name ) AS T ORDER BY T.num DESC LIMIT 1