Lots of good stove options here. Now for my two cents.

For a backpack portable (i.e. bug out on foot) stove, I'd choose the MSR XGK. Why? Well, for one thing it'll burn just about any liquid petroleum product known to man: Coleman Fuel, kerosene, jet fuel, Av gas, auto gas, diesel, fuel oil, naptha, etc. The first two will burn best, but the others will work. What fuels will be available in a bug out situation? Auto gas and diesel are widely distributed, and you can siphon from a gas tank as has been mentioned. Now the rougher the fuel, the rougher it is on your stove. If you're going to use non-standard fuels, they'll work, but make sure you've got a good maintenance kit. I would think the "Expedition" kit is the one to get.
The XGK has an excellent reputation (although no stove is 100%) as a "takes a licking and keeps on ticking" stove.
HJ