Malaysia

I think Malaysia is probably my favourite of the south-east Asian countries. It is not as cheap as Thailand or Philippines. It is not as remote as Indonesia. But they look after their wildlife and, like Singapore, they are relatively nature orientated with well set up national parks. You also generally get left alone, and you are less likely to get hassled or ripped off.

The currency is the ringitt, and things are generally still cheap.
(For converting your currency to Malyasian ringitt)

Places to go to see wildlife and experience nature in Malaysia...

One of the best national parks there for wildlife viewing is Bako National Park.
One of the most important and interesting areas in Borneo is Mt.Kinabalu. Not only is this the highest peak on the island (indeed, in south-east Asia), it is the centre of a large national park and network of protected areas, rainforest and trails in a variety of altitudes. Highlights include the peak of Mt.Kinabalu itself, the Park Headquarters , high altitude Mesilau , and lower altitude Poring Hot Springs .