I think my favorite is still the 1.5 longspring either single spring, or with the additon of a second spring "making" it a #2 double longspring. I like the weight of the trap, and I like the results. Some say too bulky, but thats never a problem in the areas I trap rats.
the dls is nice, because with the addition of 2 sticks through the springs, bank or hut sets can be made with little efort or fuss.
But the one I use the most, is still the 1.5 coil, simply because I got far more of them.
The traditonal rat trap in the big marshes here was always the #1 longspring, but unless using a stoploss type, I find them to give me more wringoffs, simply due to the lighter trap not taking them down fast enough.