My only J frame so far. I had to rush to have one and could not find an old one as I would like so I settled on a new Classic line. Truth is: I like it! And because is not vintage I don't baby it. I am also planning to keep it with the stock grips, no matter they hurt my hands the first few hundreds of shots. Now I got much better at holding it and firing as many rounds as I have with me without any discomfort. Maybe one day I will find one clean old one to add.
To answer the question: for me the one J frame would always be the Model 36 Chiefs Special snub, blued with wood grips.