Wolf Tempered Glass 2-Pack
Another quick cheap choice is the Calvary-Wolf Tempered Glass 2-Pack. These days most screen protectors come in pairs. Whether that's so you have a spare, or to cover both phones when carriers offer the Galaxy S9 as a buy one get one free deal.
Either way, this Wolf tempered glass will keep it safe. Like everything on our list, these meet 9H hardness ratings, have color-matched bezels, and nothing at the top so the sensors and front camera will continue to work as expected.
Remember, the laser cut design ensures it'll fit perfect. And while it might look a little too small, this is by design to match the curves and still give you room to use a case.