Are Pass Labs amps probably the best ever you can buy ?

Best is a relative term in that you need to understand the synergy between the Amp and speakers and pre amp.

Pass makes a great amp, but the key is finding those who have the same speakers and what they use for power.

I have my own bias and budget and those also play a role in ownership.

It is Not a simple answer, yet the journey should be enjoyable as you discover what is best for Your Ears.

@cakyol 

I am fortunate to have a friend in the business which over the years has allowed me to switch various amp & pre's in and out of my system. 
I was fortunate to have a Pass designed Threshold for quite a while, then I heard a Pass X250.5 mated to a X2.5 pre amp and that has been the foundation of my system.  Great specs, reliability, hand built like a tank, manufacturer backup if/when needed, and incredible sound. And isn't that what it's all about ?  
I don't necessarily agree with others on the alleged "furnace" effect.  As you inferred, it's Class A . I'm generally pumping 60-100w per channel which on my system and in my music room is perfect. The amp gets hot to the touch when pushed, but in standby it's cool and draws about 100w.  Turn it on and it can drive most anything perfectly without concern.  ( I'm currently using bi-wired B&W 802D2s ) . I will add that since I added a PS Audio P10 Regenerator , the amp and pre have only improved in performance. 
I would and will buy nothing else and that's my opinion on the matter. 

Happy hunting & listening ....

SHAD 

I guess since you listen to your music "Loud"....I need to tell you that I recently tried an McIntosh, model MC402. After swapping everything over from the Pass X-350 and powering it up?
  ,The difference in power was literally "astounding". Physically the X-350 is an intimidating amplifier. It is, just plain and simply, "Huge".  But the MC402 is no slouch. In fact next to the X-350, it's the largest "By physical dimensions", amplifier I have owned and about the same weight. 
The thing was, When I first powered on the MC402. I brought the gain up just a bit to hear the source that was playing. The gain was set so low that at most it should have been about 60db. 
I didn't hear anything and walked over to the media player that I had been playing with as well, and noticed it actually hadn't started. So, 
"And yes, I can feel many of you cringing , As you surely know what came next!!!"

 I "manually" hit "start". The MC402 responded immediately, and out of the corner of my eye I saw the large glass pane in my, "French Doors" just to my left bow outwards from the SPL, As I turned quickly to reach the gain control to reduce the volume I noticed "Again out of the corner of my eye", that the "cat" was in mid-air, "NOT again" I thought.  and very luckily down went the gain before any damage, "real" had been done. Over the next few days I played with the amp but it was just too much. I LOVE my music loud. Just under the threshold for damage actually. "I do keep a calibrated db meter handy".  But with the speaker system I have, which is VERY sensitive. And the peaks at certain times, in certain passages were just too much because of the "headroom" that amplifier had. This in my 40+ years of listening seriously, has never happened before that amplifier or since. So you "May", wish to give a listen to one of those. The fellow I sold it to in Ca. a couple of weeks ago simply couldn't stop calling me and thanking me.  "First time for that as well"! He had been "Bi-Amping" with a pair of MC2205's he said. And that he had wanted to try a more contemporary and possibly more powerfull amp. "Mission Accomplished"!
And I went back to my, "as I see it now", "Moderately Powered", X-350. Though according to "Nelson", It does have an "Albiet Breif", and I do forget the amount of "nano-seconds" mentioned but, An output of 1500WPC at certain times when reproducing "Detail" was in fact, available in the X-350. I will add though that as a whole I have always found the Mac's just a bit too bright for "my" ears at least. And at my "Reference" listening level.
    But if you want a multitude of power..... Try hunting one of those up, or a similar "Mac".
And give it a shot. Many do swear by them. Just not "I". 
I do wonder what kind of "Home" audio speaker would be "SO" inefficient that one would actually need a pair of their MC601's? Their use in "Pro" applications "Not-withstanding".

Pass will Pass but others wil to. Try as many as you can and try a Hegel if you have the chance. I have heard them only in an audio Show setting. As a tube gear owner I put this sollid state Amp on my check it out in my system list. In my network there is a buzzing about Innamorata AMPs. They are all tube lovers that have no objective to sollid state but Sollid state gear has to be "alive".  What that means is to subjective and a matter of taste. Only your ears can judge. Great to have such a budget at hand...many options. Don't settle in to soon and have fun.               

Pass is one of the top choices among the solid state amplifier.


But if you listen to mostly Jazz, I recommend you to try tube amplifier.

The Jazz voice will sound magical with tube amplifier.

https://forum.audiogon.com/discussions/the-most-musical-sound-in-my-40-year-s-audio-history#1659706


You did not specify your speakers.

If your speaker is efficient you can try small power SET amplifier.

But if your speaker is not efficient you had better try out PP tube amplifier with more than 100watts.

If is always important to check the synergy between amp and speaker by auditioning at your home.