For me, the Logitech Ultrathin Keyboard Cover for iPad 2 and New iPad is the best case I've tested yet. One big caveat, though: There is no such thing as the universal "best" camera, laptop or even iPad case. It all depends on your needs.
I tend to need a case for my iPad when I transport it from desktop to desktop, like a laptop computer. I want the iPad protected in my bag, easy to get into working mode very fast, and I want it held securely in place at a comfortable viewing angle. Oh yes, and I want a workable keyboard, too.
This, and more, the Logitech Ultrathin Keyboard Cover provides. When used as a cover it symmetrically provides an aluminum shell covering the screen that mimics the look and feel of the iPads metal shell. The device is held on along the long spine by magnets, much in the same way as the Apple covers.
The difference is that when you open up the clamshell like design and separate the two halves, the cover becomes a base and keyboard that the iPad locks into by magnet. Connected by bluetooth technology, the wireless keyboard is much easier for me to use than the on-screen version. Though the keys are compact and not quite so ergonomic as a computer keyboard, they give me a more natural typing experience, making the iPad the laptop replacement I was looking for when I purchased it.
This is not the case you want if you tend to work without a keyboard or work standing up. They case does not wrap around the back of the iPad when not in use as a cover or stand. This can lead to awkward moments of 'what do I do with this piece of plastic and metal". It also offers no protection if you drop the unit, or are fastidious about not scratching the back of your device.
You also need to remember to charge it. This is not something that can be done via the iPad. However once charged, the battery didn't need any recharge during the entire review cycle. Logitech claims a six month battery life on a full charge based on two hours of use a day. I can't contest or confirm that claim, but battery use was a non-issue for me in these tests.
Setting up the keyboard is almost a no-brainer. You press a button, turn on bluetooth, and you have a keyboard. Wonderful! A number of keyboard shortcut keys are included, to improve your throughput, a clever graft onto what is essentially a keyboard-less operating system.
Like Apple's, Logitech's case will wake your iPad from sleep mode and put it to bed again just by opening and closing the cover.
You can even order the cover with customized engraving, perhaps to finish the thought you didn't have room for on the back of your iPad.
I used the stand/keyboard/cover extensively on recent cross-country flights and found it a pleasure when typing or just watching a movie. Lightweight, yet secure, it is (for me) the best iPad 2/3 cover on the market.