Cruise ship holiday options

Hi everyone :)
We have one son who is 3 years old and we are yet to have a proper family holiday so was thinking of going on a cruise. So my question is what cruises are most family/kids orientated that have a range of activities for little ones and also for mummy and daddys to have some adult time? Would love to hear actually experiences and what your cruise ship route was and a ball park figure on costs? Also would like to hear any regrets?