I am insane when it comes to iPad cases. I've bought so many I could probably open my own store. I go back and forth depending on my mood.
What I generally come back to the most is the Smart Cover plus a back shield such as:http://www.amazon.com/Belkin-Snap-Shield-Cover-Apple/dp/B004X8R7VA
I like that there is really almost no added weight. I used a book style case (similar to the Pad and Quill) for a really long time, and really liked the look and protection, but sometimes the weight bothered me.
Hmm, that Aura thing looks so classy.... must resist....