The Model 10 standard barrel. I have a 10-5 4" I bought from another forum member that remains my favorite. I want a 5" barrel and I'd feel I'd then own the two revolvers that say Smith & Wesson the best. They still remain the best combination of form and function S&W has produced IMO. There are more powerful and desired revolvers I know but for me it's always been the Model 10. The tapered barrel with like new bluing is as graceful a piece of steel as I think one will find in a firearm.