Top 10 modern ATTACK submarines?

[Lucky13]

What would a top 10 list look like of today's modern attack submarines? Enlighten me...

 

[Glider]

I doubt if anyone can tell as we don't know enough about them and to be honest lets hope and pray we don't need to. Few areas of warfare have more secrecy than submarine warfare as the impact to everyone would be huge, even in a non nuclear situation.