Well, people who say there are the best either a) Do not have a good ear. b) Are of the fanboi variety. c) Haven't actually listened to a decent system.
As to why the prices are high, Bose has one of the world's best marketing department and have convinced people in a and c that they are better than they actually are and converting some of them into b.
That's not to say that some of there speakers don't sound decent, there are far far worse stuff out there. However, they don't really belong in high end discussions. The goal of audio systems (when were talking home audio given the context of your question) is to play back the original performance as accurately as possible. Bose' speakers tend to be rather colored meaning that they overemphasize certain frequency ranges and underutilized others. They just cannot be accurate to the recording. There's other issues too, imaging, soundstage presence, etc, but it's easy enough to stop at coloration.
As for what is best, I'm sure there's an implied price range in there hard to give a good answer without knowing what it is.
If unlimited, I'd say
http/www.genesisloudspeakers.com/g1p2.html and using there amps.
Mitchell