Death of a Pop Star - 9th Wonder & David Banner
Hell: The Sequel(aka Bad Meets Evil) - Royce da 5'9" & Eminem
Distant Relatives - Nas & Damian Marley
Watch the Throne - Jay Z & Kanye West
Ferrari Boyz - Gucci Mane & Waka Flocka Flame
Self Made Vol. 1 - Rick Ross & Wale +more

Which one is your favorite/best? Do let me know if I missed any...