If it's just opinion I'd say a Korth is THE BEST double action revolver made.
The Texas Longhorn Arms (Grover's Improved, Texas Flat Top, or really ANY model) is THE BEST single action revolver ever made.
Of course both of these are going to run you North of $5K easy (if you can find a TLA). Silly to buy one of those when you could buy seven or eight Rugers? For most people it's a resounding, yes. But, there are always a lot of people out there who are looking for, "THE BEST", and are willing to pay for it.
I don't think it's ridiculous to say that Ruger's are a very good value, or that for the money many people think they're the best. No mass produced anything is going to be THE BEST. In guns, as with anything else, there are diminishing returns, and a premium paid for a superlative beyond it's reality.
Willi Korth and Bill Grover were engineers/businessmen who both set out to make THE BEST pistols. Not what would be commercially successful, but THE BEST. I think they both found success, but only because they actually achieved THE BEST.