Define "best". Your "best" is another ones "no way".
Pass gets lots of accolades and praise, so they must be good! I have really no experience with them. I have a Luxman L-590AxII integrated. It's full class A power. Sounds spectacular and has a built in phono stage, which is also excellent. Others I considered were the Esoteric F-07 integrated. I see, maybe it's new, Mark Levinson - No 5805 Integrated. It has phono and digital inputs.
These are all available at Music Direct. No I don't work for them. I mention them because they have a generous 60 day return policy and they make returns easy. This is essential for trying whatever you decide to purchase; you need to try it in your system. It is the only way to know, if a piece is right for you.
I too have Pass Labs on my short list of amps I would like to try. Pass X260.8, as well as PS Audio BHK 300 Monos are my two short listed SS Amps. I have the BHK Pre with NOS tubes (the Tungrams recommended by Uncle Kevin). My speakers are Von Schweikert VR 5 Anniversary Mk 2s, and I am currently bi-amping with a highly modified Sonic Frontiers Power 1 SE+ on the top (KT150s) and a pair of custom built Class D Audio monoblocks for the base. The sound is superb, but I am growing tired of large power tube maintenance, cathode resisters blowing every 6 - 7 months, and would like to simplify. The input tubes of the BHK wouldn’t be a bother for me, as I know those amps would be a great match for my pre, as well as speakers. That said, I am still interested in owning a Pass. I owned Bryston 7BSST for quite a while, and although they were a great match for my older VR 3.5 speakers, they were not a good match with my VR 5 Anniversaries. Anyone here have experience running Pass X series monos with Von Schweikerts? I do not have a local dealer close to me, and the Pass Dealer that is 1.5 hours away does not sell PS Audio.