I dont like the direction they have taken Fallout games resently.... I'd say fallout is still a "bigger" IP, but quality wise, Metro might have it beat in future.
Necro-bump this 2020: http://gamrconnect.vgchartz.com/thread.php?id=229249
Bumb in 2021: http://gamrconnect.vgchartz.com/post.php?id=9047071