rateyourmusic.com giving allmusic.com a run for its money
I'm not going to lie, a significant portion of my music research is done on the allmusic website. Sure it's good, and comprehensive,and has well, 20 second extreamly-low-quality sound samples.
But sometimes that just not enough. Check out rateyourmusic.com and don't be put off by the admitedly shitty look of the site. You'll quickly see how suprisingly comprehensive this site and its user-submited too. Gee-wizz!