what are some of the best amplifiers

The best solid state amps are the Modwright DNA-500 and any of the Clayton Class A amps. They are all superior to the Krells, Levinsons, Sim, Rowland, etc.

The best tube amps are for low power the Coincident Technologies Frankenstein at 8 watts/channel and the Coincident Technologies Dragons at 70 watts/channel. Dehavilland makes some nice tube amps and so does Rogue.

Yes, I meant the McCormack DNA-500. But the Modwright KWA-150 is also very good. But the Clayton Class A amps are also at the top. All these solidstate amps are better than the Krells, Levinsons, Rowlands, etc.

For tube amps, if you have high effeciency speakers like Devores, Coincident Technologies, Vaughns, the Coincident 8-watt Frankenstein is a glorious amplifierat $5,000. For higher power the Coincident Dragon at 70 watts is also excellent. Similarly, the Einstein The Light in the Dark is also great.

For solid state amps, the "best" ones are those made by Clayton (Class A amps), McCormack DNA-500, and Modwright KWA-150. But the Clayton's and the McCormack's are the best.

In the tube realm, if you have high efficiency speakers the Coincident Technology Frankensteins at 8 watts/channel are glorious. If you need more power the Coincident Technology Dragons at 70 watts are superb. Einstein-"The Light in the Dark" amp is also great. You can get great tube amps under $10,000. Dehavilland makes nice ones as does Rogue. But at their price points (and even way above these points) I think the Coincident Technology amps are the best