Hardware sprites? They are so limited that I hardly know a game that would ever have used them except for the mouse pointer
They were used a lot in the good/best games. Mostly for the player sprite. But also for player bullets, score display and sometimes even for additional parallax layer. In Battle Squadron for example the (max.) two player sprites plus all the bullets shot by them plus the score display was all done with hw sprites. Some of these games
(others incl. Turrican 3, Lionheart, Shadow of the Beast) would have looked terrible if there had not been hw sprites. Because with hw parallax scrolling you (on OCS/ECS) only had 7 real colors in the foreground and 8 real colors in the background.