[ThatBeardedGuy]

I like steel when it's available, because it gives you audible feedback that you scored a hit and removes your need to figure out which of the several dozen holes you've put in your target are actually from your current course of fire.

When it's not, I prefer silhouettes. I've gotten a few of the zombie targets before just because they paint up when you shoot them, and they're legitimately a fun break from the norm.