Bass testing

Ok, so, my friend got a new sound system being put into his car tomorrow and we spent perhaps the last 2 hours searching th web for some songs with good/heavy bass. As I was leaving his house he asked me to find some more, so as I was walking home I kept trying to think of a place with good bass. Whom else would I look to find something like that then from the you Forumers. So if any of you got any good/heavy bass songs you wouldn't mind sharing that'd be great, and for genre of music, anything but rap is alright, but we'd prefer it to be along the lines of trance, techno, or metal.

tl;dr Need good bass song, would like it to be trance, techno, or metal. NO RAP

Thanks in advance.