I am looking for a best gaming keyboard too and I was trying to decide between the following:
Razer Blackwidow Ultimate 2013 Elite Mechanical Gaming Keyboard (RZ03-00381900-R3U1)
Logitech Gaming Keyboard G510
Qpad MK-80 Pro Gaming Backlit Mechanical Keyboard
And I've chosen the Logitech G510 due to more reliability and efficiency, and less costs, even I used to have Razer Blackwidow Ultimate - Dragon Age II (RZ03-00381400-R3M1) Good looking and worked fine but Didn't like it and I sold it to a friend..
Hope I helped a little