I have enjoyed Hong Kong, Singapore and Malaysia - So if you want a city experience they would all be good choices. I took a side trip from Bali to see the komodo dragons - I thought it was well worth while. I did not use a tour, but booked flights and accommodation myself, this probably meant it took longer to get there and get back, but it was an adventure. Depends on what you like and how much time you have. The forums on trip advisor are full of people who had problems with tours booked over the internet however, so be careful. I haven't been to Bali in over 10 years, but once out of Kuta it is beautiful.