How large a room are you in? What are you listening to? It sounds like music only (i.e. no games or movies). One option is to start with a pair of Energy RC10s. You can get them in black at Vanns for $300 a pair if I recall correctly. These are very highly regarded bookshelf speakers that have been supplanted by a newer model. I have a pair in the rosenut finish (all stock in this finish is sold out from what I can tell) set up in a room that is about 12x12 (and totally closed off) and they are really really excellent, even at loud volumes. In a larger room (or any room with a large opening to the rest of the house), I would want to use a sub.
Aperion makes some very good bookshelfs that hit the max of your budget (the Verus line). They are also very good. I don't have them but have listened to them extensively. I do have a number of other Aperion speakers and love them. To be honest, I'm not sure if the extra money for the Aperions is worth it over the Energys. They are better and are a bit larger, so they can fill a larger room with fuller sound without the need for a sub. But they do cost 66% more money. It depends on your specific situation (including how frugal you are). Aperion offers a 30 trial with free shipping both ways so you can try them out in your home at no expense.
There are a ton of other options. Have you tried searching for "bookshelf" over at the speaker subforum on avsforum.com? There are a ton of threads on this exact issue. Good luck.