I’m with glennewdick, ProAc D2 are a great reference.
Although
grinnell is bang on the numbers too, Reference 3A de Capo i’s are easy to drive and have a superb frequency response. I put them 2nd only because they vent out the rear which makes them a little less versatile.
jsautter is also correct bringing up ATC, a very reputable speaker, especially their active speakers. Fellow audio buffs have
criticize their passive speakers as really hard to match appropriate upstream components to.
One speaker that’s getting ink in these parts, and they’re only $1500 bucks, is the Vincent LS208’s. The German’s tend to know what they’re doing, personally I can’t vouch for them, but like I said, they’re getting ink.