ASUS EEE Pad Transformer ($389): The Transformer is a reasonably priced Android tablet that doubles as a "netbook," or small laptop, if you buy an accessory keyboard dock for $109. You can get an accessory keyboard for any tablet, but the Transformer's attaches securely, and the combination folds up like a laptop. The keyboard has a touchpad, extra ports and an additional power pack, which prolongs battery life.
Barnes & Noble allows books from other bookstores to be read, while Amazon doesn't. However, there's no video store yet, so you can't download movies for offline viewing, as you can with the Fire or larger tablets such as the iPad. The older Nook Color is still available for $50 less. It has less memory and a slower processor, but otherwise does the same job as the Tablet.
The 3G version comes with access to AT&T's cellular network, with no monthly fees. That makes it a good gift for someone who travels a lot or doesn't have Internet access at home (in which case, you may want to consider the 3G with keyboard). For $149, the touch model comes with screensavers that display ads for cars, beauty products, Amazon gift cards and so forth. Pay another $40 to get rid of those. You can go the other way and save $50 by getting a non-3G version. The 3G with keyboard starts at $139 for the sponsored model.