I like the K-frame snubs best. They are small enough for most snub uses (except pocket carry, and for some of us we may even be able to handle it in a pocket), they offer much better recoil control, they are far more comfortable to shoot (both adding up to faster follow up shots), and they hold one more shot than a J-frame. I absolutely love my S&W 65LS (3").
I'm planning on a Taurus 450 (2", medium frame, .45lc snub) in the next several months so my favorite may change.
For a J-frame I guess I'd love to have a S&W 60LS and I also really want a Taurus 85UL (aluminum, not titanium).