What iPad is the best? Ipad 1, Ipad 2, Ipad 3, or Ipad 4?
The best iPad as per you description is iPad 4. The device is inbuilt with the capability of a Wi-Fi and 4G connectivity. It has some of the best features and specifications than the other iPad devices. Check out http://www.gsmarena.com/apple_ipad_4_wi_fi_+_cellular-5071.php for more particulars.
iPad 4 has no retina display
Maybe the newest one.