Our usual stove fuel of choice is to use gas as it is clean and so easy to use. However it isn't the cheapest fuel and the resealable gas canisters are not that easy to get hold of in some countries.
In the more remote areas we have toured we have often taken a petrol stove as the fuel is available almost anywhere. With our Bikebuddie bottle carriers we can carry 2 litres of petrol between us which will easily last us 4 weeks.
The Optimus Polaris multi fuel stove gives us the best of both worlds as it will run on petrol and gas.
If we are touring in a country where we think that finding the resealable gas cartridges is a problem, we usually take a GoGas adapter which converts the pierce-able gas cartridges to resealable ones.