i've been to bali a few times.
while it is obvious that one should be bowled over by all the famed beach resorts in bali, i personally prefer the often overlooked mountainous regions in bali. a couple of times i spent about five days there and i split my stay 2 days by the beach resorts and 3 days up in the mountains.
the mountains give a refreshing touch compared to the commercialized towns by the beach. the laidback surrounding and the cool morning air and mountain dew are therapeutic for over-stressed city folks like us. find one lodging as high up as possible. believe me, the air can be more cooling than genting highlands.
in bali there is an entire gamut of accommodation that suits all budgets. you can get US$10-a-night budget rooms to US$1,000 presidential suites. it is all up to your budget.
well, my suggestion would be for you to stay at a beach followed by a getaway in the mountains so that you can enjoy the best of both worlds in bali. the most famous beach is of course at kuta. other seaside places such as sanur, jimbaran and nusa dua are popular too. you may even want to check out some of those diving or dolphin-watching day cruise. in ubud, you can find many handicraft and cultural artifacts. accomodation is aplenty there but it is not by the beach though. in the highlands you could check out kintamani and bedugul. there is not much to do there except than to soak in all the refreshing sights and sounds. but then that's the whole idea, isn't it?
bear in mind that bali has so much to offer and is significantly larger than singapore and the road network is not very advanced. hence, it may be wiser to stay longer at fewer places and enjoy yourself rather than trying to cover too wide an area and be stressed out by all the travelling.
if i were to visit bali again (which is just a matter of time), i will do the same again without hesitation. nonetheless, this is all a matter of personal preference. just sharing another perspective.