Agree with much of what has been said above. Integrateds will provide the biggest kick per buck. Here are some of my favorites between $1-2K, (but previously offered advice on the importance of amp and speaker matching should be considered in any purchase).
Naim Nait 5i - really sounds great. Don't worry about the stated power - plenty of current
Musical Fidelity A5 (used) - good, lots of head room, agree with poster above
Exposure 2010s - great bargain - good sound
Vincent Audio SV-236 MkII - hybrid - really, really good
NAD C-375BEE - great new product - plenty of power and drive and surprising amount of finesse at this price point
Anything new or used from Sim Audio
Anything used from Blue Circle.
For tube units, I like PrimaLuna, a lot. Simple, well made, good sounding, and relatively cheap. Look at the ProLogue 2