The better story would have been that finally, in this, the year of the cow, one among the city's numerous new upscale meateries had managed to dethrone our 14-time Best of Boston stalwart. Nothing doing. Mooo inherited the Federalist's matchless wine list. KO Prime has the best offal around. But for a prime, dry-aged rib-eye with a power client (downstairs) or a significant other (the more intimate upstairs), Grill 23 still rules the herd.