I listen to late night radio mashups and stuff but seems impossible to find anything good on the internet as u have to wade through all the shit.

I like absolutely anything except screamo and country music.. Tastes vary from metallica to dieantwoord so throw anything at me.

Started with LastFM. Looked at my favourite bands and they have a recommendation system which is alright.
Then rateyourmusic has a bunch of bands and albums. The ratings are shitty but they go deep into genres, good and bad.
Then (for metal) encyclopedia metallum
Then dedicated genre forums

Youtube>

Best thing to do for metal is to go on youtube and type black/death metal and then some word that sounds cool, and then listening to all the shit that comes up
there's really a lot of good shit on there that goes unheard
ex: death metal imposition, black metal plague, etc etc

private music trackers and rateyourmusic.com

xm radio got me covered for life. I need look nowhere else.

Yea, there is a lot of good metal that not many people listen to.... or even know thats on there.

I dont really like most of current metal, too much screaming and all the instruments just sort of mash just sounds likea mess.

Just my opinion

I dont know really but I keep finding 20+ awesome records every week so i must be doing something right