I have been using the Vargo Titanium Triad multifuel stove for years, and it’s my favourite lightweight stove by far. It only weighs 30g, it packs up really small to fit into the saucepan and it can run on a number of fuels. This is extremely useful as you can resupply on a long walk with whatever fuel you can find, rather than having to search for one particular type. I usually run the stove on methylated spirits, as this is readily available and cheap.
The stove is a little slow to heat water, but it’s highly efficient and tiny. Highly recommended.
You can read my full review of the Vargo Titanium Triad multifuel stove here.