The Michigan Defense Drill is the best 5v5 drill I have come across. I applies on the ball defensive principles first and then layers in helpside defensive principles. This is how it happens in a game most often. One player needs to play good on the ball defense while everyone adjusts to the helpside and communicates.

Additional Resources:

You'll find these concepts and more inside the Building A Force Baseline Pressure Defense ebook in Module 1 on page 28-30.

Further Discussion:

Start the ball in different areas.
Don't allow your offense to take poor shots. Define the type of shots you want and the number of dribbles an offensive player can use each time they touch the ball.
Encourage communication otherwise the defense will never get all five players on the floor at once.

5v5 Michigan Defense Drills