Hi..We went to bali for 15 days this year..
can spilt your stay .. good places to stay are nusa dua its an enclosed Area with mainly 5* accomodations each hotel having a pvt beach. seminayak its beautiful beach again with decent nightlife though most places close early by 10ish. kuta the beach is horrible but the best place for nightlife ubud is famous for serenity and calm atmoshphere ..beautiful tea gardens..greenery everwhere.. you can choose to stay at atleast 2 places for a varied experience.