I've had good reliable results with the simple homemade CAT stove that Jim Woods introduced. The one I use will boil 500 ml of 50°F water in about 5 minutes on about 0.7 fl. oz. of denatured ethanol. I also have a Trangia Mini that is heavier (5.8 oz with windscreen) and slower cooking (500 ml in 8-9 min) but comes with a simmer ring/snuffer and a cap that lets you save any unused alcohol. The Trangia also comes with a separate wind screen/pot support. As long as you are not in a hurry to boil water and don't mind carrying a few extra ounces, the Trangia is about as foolproof an alcohol stove as one can get. But, the CAT stove is pretty foolproof too and only weighs 0.23 oz.