I spent some time demoing Klipsch speakers. I was listening to the Synergy series, with a decent ~$200 Sony Reciever and a ~$100 Sony CDP. It wasn't an ideal situation, we didn't have a wide selection of music available. I don't have a lot of experience with high end speakers but I was with my friend who has B&W Matrix 802s and we came to the following conclusions. The horn tweeters give a very good treble. We also tried some Sony speakers and the treble on the cheapest Klipschs was miles above the best Sony. However, the Klipschs with small woofers did not have much bass. The more expensive ones with 8" woofers did, but I felt that large woofers did not extend high enough to meet the horn tweeters. There was an area in the midrange that seemed missing, which probably meant that the horn tweeter could not go low enough to reproduce those frequencies and the large woofer could not go high enough. If I were you and I was looking to get Klipsch bookshelves, I would get the ones with the 5" woofers, as they sounded the best to me, and pick up a powered sub. The SB-1/B-2 (The B-2 replaced the SB-1 in 2004 but you can pick up a new SB-1 for $120 online and from what I can tell they use exactly the same woofer and tweeter, just different styling on the cabinet), the small bookshelves with 5" woofers sounded better than the larger ones. With a subwoofer, I think the SB-1/B-2 would be a pretty good choice.
Just keep in mind, everything is IMHO, IME, etc. I don't have much speaker experience and I had a small selection of music, but I think the Klipsch SB-1/B-2 has a lot of bang for the buck. The only downside I noticed was the lack of really low bass, but a powered subwoofer would fix that and still come in under your budget. I'm not saying these are the best choice, because I haven't personally heard any of the other reccomendations, but you should definetly take a look at them.
