Fortunately - they differ enough in their sound quality and speaker matching to deserve separate threads. But perhaps it would be nice to name speaker models, not only the brands.
Reference 3A. My two monitors from the company thus far (MM DeCapo BE, Reflector) are specified at 92 dB sensitivity and an 8 ohm load. They could be driven by my 15 W/ch tube monoblocks very dynamically. Currently I use a tube amp of 100 W/ch into 8 ohms, with even more dynamics.
Some floor standers by Reference 3A are also specified at high sensitivity, and as tube-friendly 8 ohm load.
Another vote for Reference 3A speakers. Have listened to Episode, Veena and Grand Veena floorstanders with under 100W/ch tube amps and never felt any of them was underpowered. Really geat speakers and unbeatable value for money. No wonder HP was raving about them.