Easy. A Model 27-2 in your choice of barrel length and finish.
Yes, the Registered Magnum is the granddaddy and the "Holy Grail" to many collectors, but that's the problem... too pricey.
The 19 is a great gun but the 27 is far more deluxe and sturdier.
The 28 is just as strong as the 27 but not nearly as nice or pretty and for some reason the prices on these have risen to very near 27 levels and that's nuts in my book. Spend another C note and get the far superior 27.
The L frames are OK, but that's it... only OK. The 27 is better. Period.
The M27 and the 27-1 were not made for long and collectors have driven the prices up. The 27-2 was made 1962-1981 in great numbers making it the best value among 27 variants. The 3.5" barrel version is very sexy and highly sought after. The 4" was only made for 3 years and is also popular. IMO the 5" is the best looking and best balanced version. The 6" is the most common and will be cheaper than the others. The 8" is the least popular but they are shooting machines and you get full benefit of the 357 Magnum performance.
A blue 27-2 with the 3.5" barrel:
A nickel 27-2 with a 5" barrel:
A nickel 27-2 with the 8&3/8" barrel: