I wrote a post about buying a camp kitchen and a stove but we still haven't got around to buying either. There were too many other things we had to get that took precedent. So when we went away last weekend we ended up using a borrowed single burner stove. We have used one of these before and it worked fine for boiling the kettle for a morning cuppa, but the one we used last weekend seemed a little under-powered, it was finding it hard to even boil that kettle. 
The first one we borrowed was like the green one pictured top right, last weekend we used a Campingaz one like the one pictured on the the left. The issue may have been caused by us using non-Campingaz gas canisters. Luckily the others in our group had plenty of stoves and we had a BBQ with us too which we used on two of the three nights. So for our next trip we're looking at getting a proper stove.
If you go to any online camping store you will see that camping stoves come in all shapes and sizes but only a handful meet our needs as family car campers. We're not backpacking so we don't want one that packs down to the size of a box of matches. We're not travelling across a third world country away from supermarkets, so we don't need a multi-fuel one that will cook using goat dung. We're car campers travelling in the the UK who want to cook family meals: pasta and sauce, chili and rice, fry-ups, toast etc. So what we're looking for is a double burner (cook the pasta on one and the sauce on the other) with a grill (our youngest is a bit of cheese on toast addict).
That brings us down to a handful of possibilities. The market leader and the one we'll probably plump for is the Campingaz Camping Chef pictured right. This fits all the requirements, packs away relatively small and is well recommended. The only issue with it is that the grill element is apparently not wide enough to toast two slices of bread at once, despite the grill tray being large enough to hold two slices.
The other possible is the one pictured left. This looks like possible option but having read up on it I discovered the burners are 1.5 Kw whereas the Campingaz ones are 2.3 Kw. Given the problems we had last weekend I think we would be better going of the more powerful Campingaz one.
One annoying but understandable thing I have found about camping stoves is they don't usually come with a regulator (or even a tube sometimes) this is so you can get the regulator for the type of gas you want to use, but it's a bit annoying. You can get the camping chef with a regulator and bag, but the additional cost is pretty similar to buying it all separately.
One other possibility is an all-in-one stove with a stand, the two stoves above need something to sit on (unless stooping on the floor while cooking your beans is what you are into). It's also possible to get stoves with a built in stand. Campingaz make two, one based on the Camping Kitchen stove (which doesn't have a grill) and one based on the Camping Chef stove (above). The problem is that of the two the Camping Kitchen Extra stand is better but it lacks the grill. So it looks like a stove and a separate camp kitchen (yes the names are confusing) looks like a better option.
Camping Stove
We have a converter of some sort, on ours that lets us hook into a large propane tank. In this way we don't run out, plus you can get a 'distribution post' that allows you to hook both the stove and a lantern to the same tank. No more 10 little bottles of propane to take along!