The answer to your question depends on what you are trying to achieve through your weight-training regimen.Are you trying to get bigger and stronger? Or are you trying get leaner?

If your goal is size and strength then its of my opinion that you should focus on one exercise at a time before moving onto the next exercise in your routine. This allows you to focus more on what exercise you are doing and it also allows you take a slightly longer rest time which will in turn allow you to push out more reps and more weight.

If you are trying to lean up and burn calories while getting stronger then pick two or three exercises and cycle through them. I workout over my lunch breaks so I have to do this in order to get enough reps and sets in. So also use this approach when you are short on time but still want to get as tough of a workout. Here is an example of one superset that I use on my Arms day that always kills me:

Close Grip Bench Press - 1 set

Barbell Bicep Curl - 1 Set

Hanging Leg Raise - 1 Set

Rest & Repeat superset 3-4 times then move on to new superset of different exercises. Keep in mind that if this is your approach do not take any rest between exercises. Take a short rest between supersets only.

I hope this helps!