Compressed alcohol. I buy it at the local Ace hardware store a gallon at a time. I like its properties -- you can put alcohol fires out with water (it absorbs alcohol) and the fumes are lighter than air.
There are some drawbacks. Pressuring up the tank is pain, but I only need to do it every three meals or so. Lighting an alcohol stove requires getting up a learning curve. It only takes a 2 seconds of open knob to fill the lighting bowl appropriately. If you put too much in the bowl and light it, you can burn your boat down! Also, finding parts for the old alcohol stove system is difficult. No one sells an alcohol tank anymore, so I replaced my old, rusted steel tank with an aluminum tank designed for pressurized automotive suspension systems.
T. P. Donnelly
S/V Tranquility Base
1984 Islander 30 Bahama