If you want shower speakers that are a bit more high end than the other models, you will want to look for some that can be mounted flat against the wall. These are naturally going to be more expensive ($200+ per pair) but the effect will be much nicer as well.
For starters, models like this will have cords that go inside the wall during installation so the only thing you will see will be the speaker flat against the shower wall (similar to a plasma mounted flat against a wall).
Flat shower speaker mounted on the wall
In addition to having high quality sound output, this type of speaker gives a sleek, modern look to your shower.
Shower speaker setups such as these will require a bit more in the way of installation than the external shower speakers, so some knowledge of construction, wiring and soldering may be necessary. Many speakers have the installation manuals available online from the manufacturer’s website so you can take a look before you buy it. If you are unsure, it is recommended to have a professional install your shower speakers.