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

Absolutely in the team photo.

One of their greatest strengths is that while they may not be the "perfect" pairing with a given set of speakers, they typically sound damn good with everything.  So, as far as an investment that is nice to know.

I've run my 250.8 with power hogs, and with easy loads.  I've swapped out amps on the same speakers.  Typically, the pass still sounds the best.  

The 250.8 however I believe is one of Nelsons best designs.  I like it better than the 350.8 when I've heard it. 

Just has a really great midrange.

There are a number of great amplifiers out there, both tube and solid state, for a range of prices.  I have been lucky enough to have many of them from ARC and CJ tubes to a number of Rowland, Levinson, Krell and, yes, Pass Labs amps including most recently the XA100.5's.  I have not owned the 0.8 series Pass amps yet.  Having said that, a critical factor for most amps remains the speaker-amp interaction.  I have ML CLX's and Pass Labs has recommended the larger X 0.8 amps which they feel are better suited to driving the CLX's than the XA series due to its need for higher voltage and amperage as well as its punishing impedance curve.  Your taste in music and in what aspects of music reproduction  are most important to you are obviously critical as well; no amp or speaker is perfect.  This sounds trite, but I really think that you need to hear your speakers with the amps under consideration.  Others have opinions, but you may not share them.

@almarg 
I just crunched the numbers on Wolf's speakers assuming a typical room size and speaker placement. He should only require about 9 watts to get up over 101dB at 14 feet away. That figures out to about 9.5dB of gain. The SIT3 would work. It wouldn't work for me though. I need about 3dB of pre-amp gain to get where I want to be with the F5 at it's 15.5dB. It's easy enough to fix that if I wanted to. Getting it up around 19 is a matter of swapping 4 resistors. Most people do make that change when running 32V rails. I didn't. 

I've heard a top end Pass System and I'm .... mystified. I'm sorry but they don't do it for me. They're not even as good as Parasound Halo line. To my ears they are thin and not particularly revealing.

If I had the money and space I'd buy Ayre and never ever look at Pass again.

Peace.

There "is" a Nelson Pass designed vintage SS amp that for the money and to me that is "Crazy good" sounding. The "Nakamichi PA-7", is one of his "Stasis" designs he did for them and are built like tanks and rated "200Wpc. @8Ohm" and down to 2Ohm very stable as well in my experience.
  OR, the last year of that model was 225Wpc. Those are marked, Pa-7ii. 
    "No roman numerals on this keyboard!"
I have one rig put together using nine of them. "Tri-amped mains plus surrounds and a bi-amped center for watching movies". But I do need to either turn the heat down or off in the winter about half-way through a movie! They are a nice design for a class A/B and reliable.
They seem to run about $1200-1500 for a nice one, But I have seen them for 4-600 as well.
But the nice one's? "As in mint cosmetically and serviced".  I think they are a hell of a deal as long as serviced by a good rep. company. Most were bought of course by guy's that still take allot of pride in them. One I bought even had the orig. top removed and a vented plexiglass top installed so you can see that giant "Nakamichi" labeled, toroidal transformer in the front that is about 9" in dia. and the four big caps. It's my favorite one of the bunch. I do get lots of comments from friends on it. But it's not to impress anyone but, "Lil 'ole me! And they do a good job of that. In fact the "Firefight" at the end of the movie, "The Accountant"? My friends still gossip about that as we watched it the room with that rig! Amazing! 
 And, Just think of all the good that the $13,500 that you saved would do for your favorite charity! Or you could start your own!