I recently visited North Bali and had an amazing time.
We not only got to see an active volcano, and bath in hot springs, we were pampered with sheer luxury whilst doing it.
We stayed at a place called Villa Santhi. We were treated like royalty. It is right on the beach in Lovina and the sea is like taking a bath.
We went snorkelling, visiting temples, got Balinese massages and ate gorgeous local cuisine. I actually can't fault our week there.
My advice is go to North Bali not the South!