One Amp To ‘Rule’ Them All....

Only one answer for all these scenarios, and I’m shocked everyone is avoiding the obvious:

A pair of Psychron Master Legend Retro ES20 monoblocks

Hybrid design, switchibable, dual everything...

Not a fan  of Mcintosh amps and their autoformers, I have heard too many amps that are better.  The best amps I have ever heard on the most impressive systems are Burmester, 911 or 959's.  Recently I heard a system priced >$1M, it consisted of Wilson WAMM's and matching subs, 4 Burmester 559s sourced by a Linn Kimax.  It was absolutely magical!

For solid state, if I had the scratch, I'd go with Naim S1's. But then, that's because I am a Naim guy. There's a Parasound guy on this thread. More power to hm, so to speak. Parasound has never sounded good to me personally, though, and that's what matters, what it sounds like to you, the individual. At a certain point, subjectivity kicks in, and that's all there is left to it. Thus, there is no one amp. 

The question ignores that it is a dance between amplifier & speakers & really all other components in the chain. he analogy created is who is the best dancer of all time in & of themselves & in combination with all dance partners. Fred Astaire as extraordinary & flexible as he was is an entirely different dancer to Gene Kelly or female ones like Syd Charisse, countless ballet dancers or the more modern Bob Fosse. It's like picking the most important ingredient in a complex curry, not understanding the interaction between them all is critical.

I see you later modified the question to no longer look for something   that
"everyone can agree on as a contemporary standard" and/or
"One Amp To ‘Rule’ Them All...." 

To merely "competent". I'm not at all\clear why you should settle for only that or why "everybody's opinion greatly matters in the first place.  Thee is a definitive answer here however that will give you a genuine slice of the superlative at a reasonable price & definitely available to you.  The issue completely becomes consulting the person who can & will give you this answer.  Yourself. You're going to have to figure out what's most important to you aesthetically concerning music & recognize it when you hear it. If this is an end run to to get others to decide for you then you'll never be especially happy in audio or life. You will find what you want in direct proportion to the work you're prepare to put into it.  Something much more extraordinary for the money if you explore preowned options as well. Local ones where you can hear it especially.  It all comes down to how much you want your question answered.

     john1,
     
     Very good points.  
     BrettMcee seems to be looking for the best amps available that can handle the low and fluctuating impedance loads of his several models of Infinity Kappa speakers.  
     Why he phrased his question in such an opaque and convoluted manner continues to be a mystery to me, too.
     He is very slowly and reluctantly beating around the perimeter of his bush of a question for some unknown reason.

Tim