Ive tried the Samsung case on mine, but it opened and closed the wrong direction! Instead of the cover opening right to left, like a book, it was opposite. And the way the plastic is molded, you cant turn the tab around to fit the right way.
I also tried another case, also by Samsung, I think, where the tab could rotate to make the case a stand. It worked very well over all, but made the tab pretty bulky. That wasnt a positive, seeing as I am now using the tablet as my phone, since my zte warp bit the dust a few months ago.
So then i ordered a cheap folio type cover, made of tpu rubber. It works pretty good, and doesnt add a lot of bulk. My biggest complaint is that the screen is still able to sense touch from the cover itself. So if you accidentally turn the screen on with the cover closed, simply pressing on the cover can launch apps, send messages, etc. Also the black color tends to make the tab a little warmer than without a case (its a white tab) when its docked in my car. And I should mention that the tpu rubber molded hinges dont have a very quality feel when opening and closing the cover.
So, after all of that, I find myself going case-free more often than not. Out of the three styles ive tried though, i would have to say that the Samsung folio case (non rotating) is hands-down the nices one.
...If only it opened like a book...