We have a
Moko case on the HD+, which we love.
We had a similar style (but no name brand) on the HD, and the edge started digging into the housing, causing a separation! So I got my daughter one that completely encloses the tablet, instead.
For my HD I have a
Poetic, and love it. My other daughter has one, too. It doesn't really work as a stand, IMO, but it is great for a slim cover. (Not that I've actually tried making a stand out of it. I don't want to bend it all up).