At a concert especially, fans tend to stand during a lot of the performance, making it important to get seats where you can see the stage if you are short. The best option would be to sit in the front row of a section. The front row of the middle or upper level would be even better than the lower level, but all of these options would work well. If this is not possible, the next best option would be to sit somewhere on the top level of the stadium. The upper level is steeper than the lower levels, so you will have a better chance of seeing over the person in front of you.