Very tough question, because there are so many excellent candidates. My short, non-prioritized list includes:
Smith -- Models 19, 627/27, 686
Colt -- Python and other selected snakes
Ruger -- GP100, SP100, Security Six, and all the "Hawks"
FWIW, my current favorites (own two of each) are the Ruger KGP-141 and the S&W 627 Special Edition.