Both islands are very nice!
And it really depends what you are looking for!
But if I had to choose, I would go back to Phuket. But I was and I am looking for a good party and not silence. This is why I am going to return in 3 weeks because I enjoyed it a lot.
Phuket was my first trip, where I returned to Europe and was really depressed. The people, the food, the bars, the party, the sea and the beach many things I am still missing.
