I'm going to second what S Clark and Cheeseboy said. There obviously is going to be bias here in this forum that will sway towards the LS. In the early years I thought of building a system with the B&W 802d, but when I critically auditioned them more and more, I found I didn't quite like their sound. They were too lean sounding to me. Weird, despite their massive size, they sounded lean... to me at least. As Scott said, classical sound wonderful on the B&W, but my style of music is not limited to only listening to classical. I heard some hard rock and heavy metal on those speakers and was unimpressed.
Now go with the LS-6 or LS-9's and you are going to get a completely different experience all together. The speakers are expansive and smooth. Not only that, but they are the most versatile speakers I've ever used. You throw classical at it and it gives you an amazingly serene experience; you throw Anthrax, Metallica, and it handles it in spades; you throw anything in between those genres and you get an incredible experience; what's more, you throw movies at it and real power and dynamics of these speakers just begin to show their true strength. The level of speed/quickness from the LS are bar-none to what I've heard.
I've owned my LS-9's for nearly 5 years and really can't imagine another set of speakers in my system for a long time to come. The LS-X that Danny had in his room at RMAF this year have been the ONLY speakers I've desired since I got the LS-9's, just because it marries the two kinds of speakers that I most wanted together (My LS-9's with Open Baffle design). But then again the price for the LS-X would be around 10x what I paid for my LS-9's, so there's that trade-off, too.
If you have a chance, though... make sure to try auditioning each of the speakers (if possible) before you make any further decisions!