Good protection adds a kickstand to make better use of the screen and those speakers.
Here's a quick look at the Amzer Hybrid Case for the HTC One M9. It's got a soft silicone underlayer that fits up against your phone and protects the back, sides top and bottom while still giving full access to the ports and buttons. And on top of that goes a rigid plastic shell for the more serious protection.
The camera, flash and rear microphone are exposed, of course, as are the 3.5mm headphone jack and microUSB port at the bottom. There's also a small window on the top edge so you can still use the infrared remote control even with the case on the phone.
Installing the case was simple enough. You start with the silicone section, and then put the plastic shell on top of that. You might well need to fiddle with the rubber a little bit to make sure everything's where it's supposed to be — you can see in our pictures a spot along the bottom where I didn't quite have it right at first. But from there, it's a solid, simple case.
The kickstand folds down flush with the case. So if you don't want to use it, it's not in the way. But if you are going to use it to prop up your phone — either vertically or horizontally — make sure you've got it locked all the way down. Use a fingernail to open the kickstand, and then slide down that internal support until you hear and feel a click.
All in all, not a bad way to protect your HTC One M9.