I consider the big 3 Pirate land, Lakewood and Ocean Lakes.
I consider MB travel park is a slight bit calmer than the other 3.
For action, beach front camping all are good choices. If anything there can be a bit too much action/crowds during the peak summer months.
I agree Frontiertowne is much more kid friendly than Castaways. Castaways is a bit more upscale and adult oriented.
If you want to stay within the excitement/Action. The choices mentioned above are all good.
If you want a little more peace,quiet and relaxation consider. Cypress Camping Resort or Briarcliffe RV Resort. MB also has 2 nice state parks as well.
MB is a camping Mecca with lots of options,but book soon it fills up fast