[Seadog]

For the kids, those metal spinner targets from WalMart and soda cans hung from the target frame are good. Kids like to see their targets move.
For some real challenge, aspirins taped to a black posterboard are good. 25 and 50 yards, depending on the shooter's skill.
Oranges at 100 yards are very "reactive" targets - good splatter effect! Eggs are good, but tend to smell, especially in the summer.
If the shooters are good, Oreo and White Wedding cookies at 100 yards are challenging.
A buddy and I like to take turns shooting soda cans on the 120 yard berm. First shooter get's it moving, the second shooter tries to whack it before it stops.