1. Chest Press-using a machine for this exercise, it is difficult to tell if you are training both sides of the body equally. If not, you could create more of an imbalance. A pushup would be a better exercise to work the desired muscles.
2. Hip abduction and adduction machine-the biggest issue with this machine is that the movement produced reflects no typical movement that is done in everyday life. We often end up working muscles that don't need to be strengthened and can lead to injury. A better option would be to do standing hip abduction and adduction exercises as seen below.
4. Sit up or crunch machine-use of this machine often puts strain on the head and neck of the individual performing the exercise. This strain can often travel all the way into the shoulders, spine and pelvis. You're better off doing a variety of plank exercises to target the desired abdominals. Planks improve stability, as well as core strength.
Photos from conejofeet.com