One of the coolest galaxy s6 live wallpapers is curve. Its a free live wallpaper on the playstore, and the only downside is the add popups in its settings. It has 8 different themes that you can customize and make your own. I would say there is about 5 nice looking wallpapers out of the 8 that are pretty sharp, and the rest are just ok.
You can customize the look of each different wallpaper with its brightness and tone, the splash effects, the sound, the speed of the effects, and even the size.
The only real downside to the curve live wallpaper app is the add popups in the settings for the app. It is pretty annoying to constantly be clicking adds by accident. Other than that the curve galaxy s6 live wallpaper is beautiful, and you should definitely give it a try.