12:00 p.m. on June 2, 2003 (EDT)
"Best Cartridge Stove" opens up the whole personal preference/favorite can of worms. There are so many compressed gas stoves that, frankly, are about equal, that it is hard to say "this is the very best one." There are tradeoffs on size, weight (size and weight are only partly correlated), heat output, adaptability to the two different connectors (the "industry standard" threaded connector and the non-threaded Bleuet connector), cost, etc, etc.
For small size and weight, I like my wife's Markill Hot Rod, but it is a bit slower than my MSR Superfly (a lot slower than the Superfly with the hanging kit and its heat exchanger setup - fastest stove of the 17 I own - at least in warm weather, and the Superfly is the only stove at present that fits both types of widely available cartridges). The Primus MFS and Omni (in the Himalayan series) can switch between liquid fuels and compressed gas, so overall, my MFS is my favorite stove - use liquid fuel most of the time, especially when the weather gets cold, but switch to the compressed gas in summer Sierra/Cascades/Rockies (I don't go to the Smokies in summer - can't stand the 90-90 weather any more).
There are other small stoves besides the Hot Rod - Primus makes one, as do MSR, Snowpeak, and others (they all have titanium versions, and all have a version that fits with stove and small cartridge inside a very small 2-cup pot).
I would guess that there must be something like 40 or 50 cartridge stoves out there that fit the Bleuet or standard threaded connectors. I didn't even mention the Coleman X-stoves (like the XTreme, XPedition, etc). That system uses a different connector, with the cartridge design allowing use in much colder temperatures than the other two types. And I have left out the old-style puncture cartridges. Although the puncture cartridges are still available from several companies (at least the 200 and 206 size), there are very few stoves still being sold that take them (Markill does sell an adapter for these cartridges to attach to the standard threaded connector).
Ok, so here are the main trades to look at - size and heat output. Generally small size means slower heating (comparison - the Hot Rod takes 4:30 to boil a liter of water, where the Superfly takes 3:00 without the hanging kit and 2:45 with, but about 3 or 4 times the bulk and about 3 times the weight). Then look at cost (are you willing to pay 2-3 times as much for a titanium version?).
The real answer is to get 4 or 5 compressed gas stoves and 4 or 5 liquid fuel stoves (preferably switchable between white gas and kerosene). Then you can spend endless hours boiling water in your back yard and trying to decide which stove to carry this trip, like Jim S and I do. Oh, I forgot - add the different weights of pots, with and without the black header paint coating.