Bali is safe but crowded lately. Better to avoid the congested areas. Some nice day trips to the Gili islands or even Lombok can be good. Singapore is nice but not much to do for more than 1-2 days. Some other considerations are Cambodia (Angkor Wat and nearby temples) and Vietnam (several nice places to see including Ninh Binh, Ha Long Bay, and Sapa in the North and Danang/Hoi An in Central Vietnam). There is also.a lot yo see in China but I have found it can be a bit harder to get around independently.