I use the one in my avatar for sighting in, B-27's for pistol & CQB AR & AK drills, printed targets for Bullseye or pistol sight-in, and the 25 meter M16A1 sight in targets I bought a bunch of years ago, from Sportsman's Guide. I picked up zombie splatter targets for my younger son when he was @9 or 10, to spur his interest in shooting.
I used to use displays from work, but they put the kibosh on that some years ago. He had fun popping .223 sized holes in Miley Cyrus' image blown up to 3' by 3'.
Back when SWMBO and I were dating, her dad bought (what he thought was) one semi full of trade displays and their boxes from 3M. He wanted the boxes for calf hutches. Which he got plenty of, because they kept dropping truckloads off until he called them! Some of the displays ( made of Lexan) had people, full sized, on them. They made good targets until I shot the target areas out. I even made a little "Hogan's Alley", and just grabbed them from the pile which the trucks had thoughtfully deposited right where I shot anyway. One was a woman in a Catwoman-type outfit, and SWMBO shot the heck out of the throaxic region with the light loads made for her to shoot from the Redhawk I had back then.