Safe and easy to use: Gas stoves pack up small and are very lightweight. The flame of gas stoves lights instantly and can be adjusted. Gas cartridges, be it screw-ons or clip-ons, are available at most camping shops worldwide.
The allround fuel: Liquid fuel is available virtually everywhere and useable at any conditions. Handling is a bit more complex though and the equipment is more bulky and heavier than that of gas stoves.