The Mandarin Oriental, Surabaya would get my vote.

It was built by the Sarkies brothers - the founders of the Raffles, Singapore, and the Eastern & Oriental, Penang. It's a marvellous colonial wedding-cake of a place - fountains and gardens and huge high-ceilinged rooms with terraces (mine was at least 50sqm, with terrace - and that was the cheapest category).

http://www.srcf.ucam.org/~emdr2/surabaya1.jpg
http://www.srcf.ucam.org/~emdr2/surabaya2.jpg

Think Raffles, Singapore - but without the swarms of tourists (it often felt like I was the only person there), and with an even more pronounced land-that-time-forgot air.

There's a good selection of restaurants, and a top-notch new spa. The service is superb - though not all of the staff have perfect English, they all know your name within a couple of hours, and go out of their way to help. (Mandarin Oriental service at its best, in other words.)

Surabaya itself is a short flight from Bali (40 minutes or so). There are several flights a day, and they tend to cost about $45 one-way. Though the city itself has few attractions, there is one rather special option just outside it: a pre-dawn tour to Mount Bromo. You leave the hotel at midnight, in a private car, and arrive at dawn, for sunrise over one of the most spectacular landscapes I've ever seen.

http://www.srcf.ucam.org/~emdr2/surabaya3.jpg

The cost - well, I stayed there a month or so ago, and got my room for $55, including breakfast. A three-hour Spa treatment was $35. The tour to Mount Bromo (eight hours in a chauffeur-driven car, with driver and guide) was $100. A room service dinner was $7.

I wouldn't recommend more than a four-night stay (unless you want to spend all your days relaxing in the gardens and by the pool), but staying here would be a wonderful counterpoint to a few days in Bali.

The only problem is... I just checked the M-O website, and the Surabaya hotel has disappeared from it. It's still bookable on Expedia (and through better-value local agents like agoda.com) - but if M-O are offloading it (and I really hope they aren't), then it's probably a good idea to stay sooner, rather than later, before the effects of any new management start to become felt.

Anyway - hope this helps...