There are many great speakers that have already been mentioned (I’ve heard amazing things about the Fleetwood Devilles). But here are two more for your consideration:
1. Raven Audio Corvus Reference Monitors - I am currently running these in my system and after researching/auditioning several speakers, these were by far the best - transparent, liquid mid range, dead center image, and especially excellent with vocals. They are on the big side for bookshelves, which gives them the ’disappear in the room’ quality of bookshelves AND the resolution and clarity of floor standers. Finally, because they use a sealed enclosure, you can put them right up against a wall/bookcases which is really important for me considering my listening room is 12X12 and filled with bookcases.
These speakers are used in recording and mixing studios around the world... I can’t recommend them enough.
2. KEF LS50 Metas - While typically not thought of in the same tier as some of the other speakers on this thread, I think you have to give them an audition. These are amazing speakers for their size (especially if you’re running them with subs in your system). While I ended up keeping the Raven Audio Studio Monitors, I had a hard time letting the LS50 Metas go (especially considering their price!). I think these might be the best value for dollar in the entire Hifi universe. Completely transparent and extremely cohesive sound.
Here is my full review of both speakers:
good luck!