The cheapest Galaxy S10 phone is $799.99, so you're probably going to want a case to keep it protected. They're also made of glass on both the back and front, which is likely to shatter when dropped and is expensive to replace.
The case that's right for you will depend on personal preferences, like whether you care about your phone feeling bulky or want both the front and back of your phone to be protected.
Your options are also a little limited right now because case makers are just starting to roll out new models to fit these photos. That said, we rounded up the case makers we trust below, so you have a good place to start.
A good case will generally run you between $12 and $70 depending on the company, the model of your phone, and type of case you get. There are cheaper options out there, but if you get a case from any of the companies below, you'll be in good shape.