The quickest flights to Bali take around 17 hours and cost from £580 return. Singapore Airlines is a great option and also allow to include a short stay in Singapore. Malaysia Airlines has excellent connections via Kuala Lumpur, and Qatar Airways has good deals. You can also consider flying into Jakarta and returning from Bali. This way you may also include a short trip to Kalimantan (Indonesian Borneo) and visit the fascinating Java.