What 2 channel Amp would you Buy for $6k?

Nobody can recommend an amp by itself without knowing your sonic preferences and the rest of your chain from source to speakers. Ignore any and all advice from those who do. And, if you want good advice, then provide this info.

ljgm is exactly right. 
We are living in a golden age of hi-fi and there are ... what? 20 amps? 30 amps? that would suit your needs.  All info would be good, but to fine-tune the options at an absolute minimum you should include your speakers.  In fact the amp/speaker combination can be seen as a single unit ... active speakers anyone. 
(I am running Pass Xxxx.8 at the moment.  If you can live with its downsides of the .8 - weight, heat, warm-up time then it will drive almost any speakers in almost any room.)

I agree with the McIntosh MC-452 comment above.  I spent the same amount for a mint condition six month old unit and haven't looked back since.  Imaging increased significantly from my previous amp (MC-301).  Go for it. 

By the way, speaking of McIntosh amps, macs always under rated their specs, for example my MC 601 monos (600watts) are actually over 850 watts in reality. The 501 are probably in the 700 range.

It’s hard to say what you will like in your system. If you have a local dealer, maybe they can let you borrow a few different amps. Else I suggest purchasing an amp from someone that has a generous trial period / return policy and will not hassle you should you want to send it back.

I use a Sanders Sound Magtech. It’s wonderful and dynamic and right at $5 with lifetime warranty. It’s 900 watts per channel into 4 ohms. It has 20 transistors per channel in the output stage, which can handle 7000 watts. For this reason there is no protective circuitry like other amps. That means no chokes!  It doesn’t get hot even at full blast. It can be left on all the time and uses next to no power at idle. It’s the only fully regulated transformer; it regulates both current and voltage. And it has been an Absolute Sound’s editors choice for many years now.

If I were to dare try another, I’d want to try the PS Audio BHK Signature 250 amp. It’s a little more than what you want to pay, but I think PS Audio will give a good discount if you trade in your amp to them. Just a thought.

Best of luck!

Jason

I would not spend $6,000 on an amplifier. There are plenty of good value amps out there for 1/3 of the price. Just make sure you get adequate power. Look into used gear or even pro audio. A used McIntosh would be a good choice. +FD