Best speaker under $500

They say you can be a project manager by mastering two phrases - "It depends" and "We can't tell with the information presently available". Depends on what you have to drive them - any recommended pair, not just Jim's Apogees. Are you willing to buy used? And do you want stand-mount (then you've got to budget for decent stands) or floorstanding? And, of course, the usual questions on your room (size, finishes, etc) and listening preferences (genres, volume, etc). Did you really think this was going to be that easy? ;-)

OK, more blind reponses/suggestions which could be available used in your range should include (generally in my order of preference): Vandersteen 2's in some variant, ProAc Tablette in some variant, NHT 2.5i, PSB Stratus Bronze, NHT S1/S2, etc. I have heard all of these set up well and sounding great - but in very different conditions and with very different gear ahead of them. YMWV (Your Mileage WILL Vary) :-)