From March-October (and in the SoCal high desert, in the winter): Esbit, first the original model, then the wing stove, now the bottom of a coke can to hold the tab and a carefully calculated pot stand make out of some metal mesh something or other. It's been great for me over the last 5,000+ miles and I am sure it will do me well this summer for 2,500-3,000 more miles.
I love seeing how much fuel (in tab form) I have left, it makes me not stress about it. I also love how if I need to make a fire with wet wood, I can use it to start the fire and it drys out the kindling so I can get enough heat/warmth generated (I am talking about responsible fire building here)to dry out more wood and keep it going. I've had to do this on occasion for me and/or other hikers who really need to get warm but were very, very wet.