Agree with Seandtaylor99 about the LS3/5a, with the only question being your taste for rock. Also, they tend to go for around $800 here and on ebay (I have 2 pairs of the original Rogers 15-ohm type, so I tend to notice).
I recently picked up a used pair of Spendor S3/5s used for $600, which I think might actually beat the LS3/5as. Slightly warmer sound, soundstage a little deeper and fuller on the bottom. Think you'd like the top. Need stands, as several of the other recommendations do, so have to factor them in to your budget. There's a very favorable review on the EnjoytheMusic.com site.
I recently picked up a used pair of Spendor S3/5s used for $600, which I think might actually beat the LS3/5as. Slightly warmer sound, soundstage a little deeper and fuller on the bottom. Think you'd like the top. Need stands, as several of the other recommendations do, so have to factor them in to your budget. There's a very favorable review on the EnjoytheMusic.com site.