One could conceivably camp without ever having a stove, but heat makes some things taste better, and a hot drink is often enjoyable after a tiring day.
Whilst I'm aware of alcohol stoves, and have used hexamine extensively, I find that gas stoves are my favourite to cook on for 1-3 people.
I've used two types of gas stove: the small, light kind which is essentially a valve that screws onto the gas cannister (the Snow Peak Gigapower), and the shielded, high-efficiency type (the MSR WindBurner).
Whilst the Gigapower stove is very light, it's only suitable for use in a stable, sheltered location, as when anything heavy (read: a pot of water) is put on top, it becomes unstable. Whilst a wind shield is available, one has to remember to pack it, and it's a bit fiddly to use. Hot water in about 4-5m.
The WindBurner, however, comes with fold-out feet to stablise it against falling (they attach to the base of the cannister), and the cooking section screws into the heating section for added stability. I haven't experience it fail to start, and it reliably makes 500g of water hot in about 2m.
With the above problems, one could be curious as to why one would use something like the Gigapower: the answer for me is packable size. Whilst the WindBurner packs down to very elegant tube, it is a monolithic size that can take up a lot of space in a smaller pack. Using the Gigapower, it, a gas cannister, and a Snow Peak X-Pot can be easily distributed through smaller spaces in a pack.
Whilst it looks like a blow torch, the Gigapower is also more flexible for cooking on: whilst one can control the flame of the WindBurner, I've had more success in simmering and more subtle cooking that simply boiling water with the Gigapower. It also can work with any pot that it can bare the weight of, unlike the WindBurner, which only works with WindBurner pots. Given how much I like the Sea to Summit X- series of collapsible cookwear, that is a bonus.
Silly Stove Accessories
I shamelessly bought a Snow Peak Ozen Solo table: this has earned me some mockery, but it provides a small, light, easily stowable flat surface to cook on. The person drinking the hot cup of coffee has the last laugh...