Way way back my then girlfriend and I travelled to Canada for a couple of months one summer whilst we were students. In Vancouver other travellers kept mentioning the Mountain CoOp. We tracked it down (without the aid of the internet or mobile phones) and spent a glorious afternoon spending money we hadn’t then earned on kit that we still have. The prices were so low and the range so massive in comparison to anything we had at home, that it felt rude not to! Our prize purchase at the time was a stove. An MSR Whisperlite International to be precise. That was 24 years ago to the month. It's been on a fair number of trips over the years and still works to this day, albeit pretty battered.

 
It says a lot about a brand, and about a particular model, that 24 years later the name has not changed, and neither, essentially, has the stove. It is virtually identical in size, it has the same three leg-pan-supports which fold in together, but splay out to make a very solid and low profile cooking surface. The fuel hose still has a lovely burnished brass weave to its outer, and the fuel bottle is still a deep cherry red. The pump mechanism is a shade shorter, but is pretty much the same principle. It screws into the top of the fuel bottle where it needs to be pumped to create the necessary pressure. The jet has a built in shaker needle which should be shaken up and down a few times prior to lighting to make sure that there is nothing clogging the hole. The simmer valve, also built into the pump, is loosened to let out a little fuel into the dish. There is no integrated lighting mechanism, you need your own flame. The raw fuel is burned to create enough heat to warm the loop of fuel pipe which pokes up through the dish, meaning that when you next open the simmer valve, the fuel passing through is hot enough to burn properly and fiercely. The simmer valve gives you real control over the strength of the flame, boiling water in a matter of minutes. If it slows, it's a simple matter of pumping the bottle a few times to increase the pressure - something which is lacking in the more modern gas stoves.
 
The stove comes with a tool for dismantling the thing lest you accidentally sully it with dirty fuel and need to clean the various mechanisms. There is also a spare jet - the one which comes pre-installed is for burning  unleaded petrol and white gas (Coleman Fuel etc), the spare is for kerosene (paraffin). There's also a spare O-ring for the pump, and some pump cup oil. Lastly there are a couple of heavy duty foil shields, a circular one which sits underneath the burner to reflect heat upwards and protect the floor, and a rectangular one which is unfurled to create a wind shield around the perimeter. Truth be told our fil shields on our old stove died a death a decade or so ago.
 
It retails at around £85. Divide that number by the number of times you might well use it (24 years, 10 times a year (conservative) = 35p per use plus fuel) and you clearly have a bargain.
 
More info on the MSR website.