You might think about visiting Indonesia it has the ingredients for great waterfalls. Lots of mountains and volcanoes, lots of rain, and there tends to be lush green surroundings around the waterfalls. I haven't seen a lot but I think Air Terjun Madakaripura and Air Terjun Coban Sewu would certainly make an Asian top 10.
Have you seen the various waterfalls in Jiuzhaigou, China? I thought those were pretty good too (although pretty crowded too).