Best small, desktop speakers, $500 or under (new or used)

Honestly, my old DCMs give me 90% of what I think is awesome, snare, piano, vocals, and the 'wrong' stuff is modest enough not to bug me. My old Tukans were good for me at under $400/pair. Most ADSs I hear give me most of what I like. I'm sure the $1500 speaker can do it better, but maybe not. They give me more base, but the high end is too subdued. Or they soundstage is super big, but the sensitivity sucks for my 60 watt amp. ALways a trade off.

Check out Orb Audio.I used to have some along with a little sub for under my desk.https://www.orbaudio.com/

I just got Vanatoo's T0 and they are fantastic - especially with the a sub... 

Last month bought a B stock Vanatoo Zero pair for $319 for my computer.  They looked new and I am very satisfied on sound. I have had some pretty nice desktop speakers in the past, these top them all. 

Nobody is going to suggest a pair NHT C1 ?

https://www.nhthifi.com/products/16548-c-1-bookshelf-speaker

Now Hear This being one of those long standing, good sounding speakers brands that's quite affordable. Easy to drive, well made and doesn't try to lend 'it's own' sound.

I'd second the Paradigm ATOMs that others have suggested. Still pretty hard to improve on for the size and price.

The powered Adams are for tracking / mixing and while they will reproduce a dynamic, detailed and full scale range of what's been recorded they're meant to be impartial and they are. No imaging what so ever, that's for home audio speakers. I use their big brothers at work in the studio and they're great but I'd hate to have to listen to them for long at home. IMHO