Speed lifts (e.g., box squats, speed deads & speed bench) are essential to increasing strength, acceleration and power. Loads around 60% 1RM should be used and moved as fast as possible. Accommodating resistance (e.g., bands and chains) can be applied to further challenge your ability to accelerate the load. Obvious explosive exercises that should come to mind are the Olympic lifts (e.g., clean & jerk and the snatch) however, medicine ball throws and kettlebell swings also fit into this category as well.
If you want to get strong you have to lift heavy, sure, using light weights for high rep sets may give you some tone but doing so will never make you strong.
Lifting heavy requires a large amount of tension. You will be forced to recruit muscle fibers in places not normally directly activated by the lift. Tension is strength. The greater the weight the greater the amount of tension required.
This means systematically increasing your work load. This is a very important concept as doing the same thing over and over for extended periods of time will eventually yield no additional benefit. Without progressive overload you will be spinning your wheels and moving nowhere fast!