Well of the things that I've heard from that era, some already mentioned.
Ampzilla.... Although the Son and Grandson sound better.
Any of these with updated parts are excellent.
Heathkit AA-1600 & AA-1800. Marshall Leach Amps, same as the others, with updated parts, surprisingly good
Sumo Nine... Same, New power supply caps, replace most of the ceramic disc and this is an amazing amp today.
Sumo Andromeda, More power, but in my opinion, not as good as any above. Odd because the Nine updated is probably the best by a small margin.
Dynaco ST-70 in Tubes and ST-410 in solid state.
SAE Mark series/00 series and 01 series... (not all, but many are really good with some decent parts upgrade.
Sony TA-N80ES excellent
I'm sure some would say Hafler... DH500, I Had one, it was ok
Eagle Kinetics pretty good
The Pioneer M22 has been mentioned, didn't have the power of the Spec's but sounded much better.
A lot of people liked the Yammys… not me
Kenwood L07M.... really not bad 150 watt mono amps
The Carvers of that Era, I did not like at all
The Adcoms everyone knows those
Phase Linear... several liked them, not my cup of tea
Kinergetics Research was certainly decent to very good depending on model.
Nikko had a ton of Amps, I've heard at least 1 that was pretty good and 1 that WAS NOT... sorry, don't remember models.
Amber 70 was a decent sounding amp
Threshold had a couple of good amps then...
A lot of people like the big Rotel amp out then. I thought it was mediocre
Of course Krell had the big KSA amps out, they were good
Harmon Kardon… Don't remember, but one of the Citation amps was good
Ok, I'm blanking on any more for the time being, maybe more later