At the moment the iPad is the undisputed king of all tablet computers. It sports an 11-inch screen and runs a version of Apple's ( AAPL) OS for portable devices, now called iOS4. There are two separate models -- one with Wi-fi connectivity and the other with both Wi-fi and AT&T ( T) 3G networking. You can also choose 16GB, 32GB or 64GM of internal memory. Prices range from $499 to $829.