SELECT *
FROM video_category
INNER JOIN category ON category.id = video_category.category_id
INNER JOIN videos ON videos.id = video_category.video_id
WHERE category.id = " .$_GET[id]
SELECT v.*
FROM video_category
INNER JOIN video_category vc ON vc.category_id = video_category.category_id
INNER JOIN videos v ON videos.id = vc.video_id
WHERE video_category.video_id = {$_GET[id]}