WSM and a Weber Summit S-670 uber gasser are the core of my current set. I also have a Weber Q-100 portable and an old no-name portable I use for camping or tailgating (neither of which I have done in recent memory). WSM is a 2005 18.5" model and I've modded it to also work as an electric by making a spare WSM door mounted with a 1,300 watt element controlled by a Auber PID box. The e-WSM can crank out some mean jerky, snack sticks and smoked sausage and be converted back to a traditional WSM in about 10 seconds. Oh, I also have a Orion "cooker" but it usually serves as the holder for the WSM dome when I'm smoking, checking temps, etc... as I have not used it in forever.
I have a large McCall warmer cabinet I picked up for super cheap and intend on converting into a super electric smoking cabinet "one of these days". I keep putting off the disassembly as getting all that blown in foam insulation out will be a pain.
So favorite.... Would have to be the WSM from what I have now. Gasser is convenient, but it's not the same flavor. But they both have their place and purpose.