As I full of expectation on ultrabook,so I don't think a tablet is good,but the samsung galaxy tab is my choice if I have to choose one.
The Toshiba Thrive is a good tablet. It can accept a full size USB drive and also has an HDMI port. You can check on Ebay or Amazon to get it at a good price. The Blackberry Playbook is also good but has a mini USB port and a mini HDMI port. You use the supplied cable to connect to the devices. Blackberry and other retailers have been selling the 3 versions (16GB, 32GB and 64GB) on sale since Christmas season last year. In any case, you can get it at a good price on Amazon.