If you train on a regular basis and want to change everything for a week or two you should try 100's.
With a simple Olympic barbell or any other barbell, you squat, dead-lift or bench-press 100 reps without stopping. The challenge is to increase the weight lifted for the single set of 100 reps.
Obviously one needs to warm-up correctly but doing one set for bench-press, squats,dead-lifts and military press is a tough workout even if light weight is used.