I have to give the edge to YouTube. It's great for new(er) music as well as exploring stuff I haven't gotten around to yet, but the real value is in the recommendations on the sidebar. Even if I like one unknown album out of ten that I click on, I feel like I'm ahead of the game, and whatever or whoever generates their recommendations actually does a great job of finding common threads. There's a lot to wade through, and I find that I have to be in the right mood or I'll get burned out quickly, but I seem to have more frequent success with that (for metal) than any other conduit, even personal recommendations. If it's an area I don't know as well, like jazz, fusion, classical, or hip-hop, I prefer getting starting points from my friends.