Pass Labs vs Mark Levinson vs Parasound - best 2 channel amp used under $2,500?

I’ll 3rd the Bryston.
You can pick up a used 4BSST for around $2,000.00
or a 4BSST2 for around $2,500.00. If you can find used from a dealer, either would still have the remainder of it’s 20 year warranty. Not only are the Brystons incredible sounding amps, that have no problem driving difficult loads, there is a reason Bryston can put a 20 year warranty on their products - they are very reliable and well built.
I had a 10 year old Bryston 3B, that started having a problem with the switch. I sent it in for repairs and about 10 days later I received it back with a new switch installed, along with a few other internal parts upgraded, re-biased and brought back to new spec - all at no cost, except shipping. By comparison, I had a 3 year old Krell that had the rt. channel go out; when I called the service dept. at Krell, they said that they no longer serviced that model (I was not asking for warranty, just to get it fixed) as it was being replaced with a new model, but they would be most happy to sell me the new model for a mere $6,500.00 - how good of them.
Both Pass and Parasound are very good amps, but, for the money, you would never be disappointed with the sound, performance or reliability of a Bryston. JMO...Jim

With his size room, about five times the volume of my room, I'd say he needs some real juice to play sound at realistic levels.  With average efficiency speakers we're probably talking 200 watts minimum. 

Ive owned all of what you listed.  Look at an NAD M22.  Seriously.

lorenc1where are ya?