Stay at the Four Season
I'm actually in Bali right now and have stayed at the two four seasons hotels and the Ritz. I would definitely recommend the Four Seasons over the Ritz. Although I did not stay in a villa at the Ritz (regular room), I can tell you that, in general, the service at the Four Seasons puts the Ritz to shame. No matter how nice the villas are at the Ritz, you cannot make up for the relatively poor service at the Ritz. I found the service at the Ritz in Bali to be poor even compared to other Ritz properties and well below the service I received at the Four Seasons.
I also highly recommend the Four Seasons at Sayan.
Cheers,
Brooklynflyer