There is no need to create an eMusic account, to see the charts, and other data at eMusic. You can also listen to short clips of any of their downloads before signing-up. I suspect price differences between tracks may distort the relative popularity of some tracks, but hopefully their monthly download approach limits that effect, and it is an excellent place to browse for music of all sorts.
Unsigned bands are out there keen to be heard, but the profusion of sites catering to Unsigned Bands make it hard to know where to look for new Techno tracks.
Catz ‘n Dogz
Gui Boratto
Carl Craig
CDs.