Well is best to investigate that by have conversation with experienced person like personal trainer or somebody who exercises from long time. Also we have uncle Google – use it for search the best solution for you.
For me, personally, exercises which make me sweat are the best. If I train my thighs or legs, it's not that useful since I don't sweat which means I am not burning any calories. I'm just stretching the muscles. But arm and core exercises are the exact opposite.