I'm a sucker for the Russian stuff, particularly the Akula (mmm... there's a surprise considering my modeling thread I hear everyone say). It might not be the best sub in the sim, and the model is not very much like a real one as far as looks go, but it is close enough and the thing is quite capable when you learn its nuances. Being able to fire the squall torpedo is great when the gloves come off and stealth goes out of the window, too.
Chock