My Euro style adapter has worked in 99% of situations in SE Asia. Lots of places in Thailand have a hybrid Euro/USA plug that is quite genius. I can't recommend more getting the Monster Cables to Go adapter that has three USA plugs and two powered USB plugs in it. You'll still need to use the adapter but it cuts out a few USB chargers.
Programs: UA 1K, all the major Airline, Hotel and Car Programs
This is what I like. Smaller, lighter, cheaper and better than those big monsters. A couple of trips to China ago, I had an expensive big multi and this--this one fit the plugs better and I can carry 2 of these instead of one of the others--When in a less than 5 star hotel that doesn't have US style plugs so I can plug in both laptop and usb chargers. Heck even taking one of these can be two adapters because many hotels in asia have both round style and angled plugs--the two halves can act as independent adapters.
This is what I like. Smaller, lighter, cheaper and better than those big monsters.
Yeah no arguing that this one is smaller than the usual "universal" ones. But why carry anything like this when all you need is a Europe-to-USA plug?
Between my USA plug and the Euro-to-USA plug, everything is covered in SE Asia. I've never need anything but these two in Vietnam, Cambodia, Thailand, Laos, and Indonesia. I used to carry that bulky all-in-one adapter that had the UK monster plug and the Aussie plug, and never used them.
Sadly the map is a little hard to read. It does say some places in China use the Aussie plug but I bet that's changing fast. Any product you buy in Asia these days comes with a standard Euro style plug.