I now use a Longshot target cam, which has improved the quality of my range time dramatically.
Previous to investing in a target cam, the easiest for me to see hits was either the standard NRA targets, plain white, or the shoot-n-see targets everyone else mentioned. If I'm at 100 or 200 yards, I mostly use shoot-n-see targets now, because it's just easier to see my hits without setting up a camera or adjusting my scope.
You can even get fun shoot-n-see targets, like my zombie pizza guy, if you're tired of the boring old bullseyes.