RAVPower Fast Charging Puck
Last but certainly not least, is what I use. the RAVPower Fast Wireless Charging Puck. This thing is extremely small, thin, fast, and it's affordable too.
The RAVPower charger is a small little plastic wireless charging pad that supports 10w fast wireless charging. They added long strips of rubber feet on the bottom, and rubber strips on the top too. This way your shiny new Galaxy S9 is completely safe while getting the fastest recharge possible.
You won't get scratches on the back glass using this. That said, they also confirm the charger works with cases, as long as they're not over 3mm thick or have metal on the back. I can confirm this works great with the Galaxy S8+ inside a case, and still does the fast wireless charging.
This does a little of everything, and it's cheap.