Hi,
Really don't know about "the best" as I haven't heard/used more than a half a dozen units, but I've had extensive experience with both Rogue Audio Sphinx v3 and Peachtree Audio 150se, both of which can be found these days for a little less than 1k.
IMHO, both of these integrated amps are outstanding and offer performance that is way, way above what one expects at their respective price points. Both are powerful and authoritative enough to drive Magnepan LRS, notoriously difficult speakers to drive. The Sphinx is really one of the very best amps I've had the opportunity to hear, even on comparison with other much more expensive units.
In short, I would recommend either one, depending on your budget, associated equipment, sources of music, preferred sound signature, etc. Both are currently available used online... good luck and let us know what you finally acquire.