Surprised no one mentioned the Svea liquid-fueled backpacking stoves. I used one for years (still have it) deer hunting in the mountains. Stuffed away perfectly in my day pack. It was always nice to take a break, have some lunch and a hot cup of soup or coffee.
The easiest and quickest stove I have consists of just a burner by Coleman that can be screwed onto most any propane cylinder. I keep it in a GHB along with a small container of propane.
A SOLO stove with alcohol burner is stored away in another bag. The alcohol will disappear if you don’t keep check on it, but it can burn biomass as well.
Although our VW Westfalia has a two-burner progane stove installed, I also store a MSR ‘Whisperlight’ and fuel just in case, or if we may want to leave the bus for a day on a hike.
I have one of the Coleman two-burner camp stoves. Must be 35 years old! I use it mostly when we loose power. I converted it to propane, so I bring in a 20# propane cylinder to fuel it.