I have a passion for the old S&W K frames. It seems as though I cannot leave one on the rack after I spot one in a pawnshop. In my opinion, the K38 is the cream of that crop. Here is mine. It is my favorite revolver. I bought it used at a pawnshop for $175, put on the Hogue Monogrip, and never looked back. It has to be the best handling, smoothest revolver I have turned a cylinder on. I enjoy the old M&Ps and Model 10's as well, but when it comes to shooting, this one is tops with me.
I purchased a Model 10-5 a few months ago (4 inch tapered barrel). It is the most natural pointing handgun I've ever owned. The trigger was smooth as silk. I'm looking for another K-frame but they seem a bit too high here. I saw a Model 15 the other day for $389.
To me the ultimate S&W is a model 14 6" full lug 38 special. I have been trying to find one of these for years. I have an older model 16 32 H&R Magnum 6" full lug that is a pleasure to shoot.