Indeed I like model 66 the best so far. I've tried it against 686 and 60 in S&W line and also against Ruger GP100 and SP101 on the range. So far and fit and feel of 66 seems to suit me best. I am going to give it another run against 686 and if my previous assessment confirms I will be looking for either Model 66 or Model 19 used in mint condition, since they are no longer in production.
Although I have to say both S&W 686 and Ruger GP100 felt like superb guns with good comfort level and great accuracy! May be just a little too bulky for my liking...