Proper music nerdery comes in many forms, but the tendency for DJs on 6 music to quote the label something was released on is a particular favourite. It's less common now, but some music shops used to categorise their stock by label, which is quite incredibly alienating to all but the biggest dorks.
On the whole I'm not certain labels matter that much, but it's also undeniable that just by being released on Warp or Stones Throw, you already know what you're letting yourself in for.
Blue Note and Deutsche Grammophon are somehow trustworthy. So established in Jazz and Classical respectively, it's like a Hallmark. Agnes Obel's album Myopia somehow came out on both of these labels which is about as huge an endorsement as I can think of.
The video for Island of Doom is superb.