Toribash
My dad has pirated a lot of music for the last 10 years. So I have a whole page of bands, which leads to a whole page of albums...
I have 50gb of music, and I've only paid for 3 albums in my life.
  1. RATM- Live At The Olympic Auditorium
  2. MachineHead- The Blackening
  3. Chimaira- The Impossibility Of Reason

The rest I have stolen off friend's iPods or DLed.
I have only DLed 1gb at most, and my iTunes library is 50gb.
infamous
I either check the "related" section on Youtube when watching videos or sometimes I look up bands on myspace and then check their friendlists.
Friends, YouTube, television [MTV, etc.], Radio, ...
last.fm and pandora is good place to find music or just google. 'your top 10 metal bands' and surf in forums :3
[Sigma]
And the second largest penis in animal kindom
word of mouf really

also, if it is played for more than 3 times in an hour in localradio/MTV it wont be in my playlist for about... i say a year or so
...
Friends, (Hey Monday - Homecoming) sister, (The Fray - Little House) radio, (Nickelback - Gotta be Somebody) random music in stores. (Switches - Lay Down the Law)