Aolander Tempered Glass 2-Pack Kit
If $7 for three sounds too good to be true from Mr. Shield, consider this 2-pack from Aolander. This is a brand we've used in the past and can comfortably recommend.
You'll get a strong piece of glass that's precisely cut to match the Pixel 3 XL's odd design and huge notch, including those dual front-facing speakers and cameras. They round the edges, then color-match the entire bezel so it'll look good even if your installation is a little off.
The glass is slim enough to fit under a case, rounded on the sides to prevent chipping, and has all the usual coatings and durability ratings one should expect. Plus, it's a 2-pack in case one breaks or you mess up the first installation.
Aolander offers a second "Not Pink" or brownish colored screen protector, but we're not sure how it looks. Additionally, we'll update this list as we test and try more screen protectors, or other brands we know and trust release options worth considering.