These RTi A1 speakers from Polk Audio are perhaps the best bookshelf speakers that can be purchased for under $300. They have an excellent sound that rivals speakers costing many times more. Robert J. Reina from Stereophile Magazine had this to say about the speakers:
I enjoyed every minute I spent with the RTi A1. The speaker’s greatest strengths — the natural and detailed midrange, the excellent bass extension — are unheard of at this size and price, and its minor deviations from neutrality have been so carefully thought out and balanced that I wanted to mine my entire record collection, playing more and more different types of music.
A total of 32 reviewers on Amazon rated them an average of 4.9 out of 5 stars.
The RTi A1 speakers from Polk Audio are available from Amazon for about $255.
Another excellent speaker brand is Bower and Wilkins. If your bookshelf speaker budget is around the $500 range, you might want to check out the Bower and Wilkins multimedia speakers.
I am an audiophile that prefers the sound of bookshelf speakers to floorstanders. While I acknowledge that I am in the minority, I simply prefer the clarity, balance, and smoothness of the smaller speakers over the (sometimes) booming nature of floorstanders.