I have tried all three. I have to say that the only time I've lost a significant amount (2 stone) was while I was going to a meeting. However over the past couple of years I have joined, not done great and decided to go it alone because I begrudged paying to be told I was still the same/put on, and still not lost much, if anything. So it is all down to personal motivation for me - going to a meeting does not necessarily provide me with that.
Having said that, despite switching constantly between meeting/no meeting/online/changing to SW/ back to WW, I may not have lost a great deal but neither have I put on, I do manage to hover around the same weight.
At the moment I am feeling motivated. Okay, I've not been any great shakes in the actual losing department so far, but for the first time in two years I have not quit my meeting yet.