Is this the album that started speed metal? Or did Motorhead get the ball rolling by fusing punk rock with metal? Halford or Lemmy? (ok, that's an impossible one to answer!)
I think Lemmy should get credit for kicking metal in the ass in the late 70's when Sabbath, Purple, and Zeppelin were declining. Judas Priest helped keep metal alive too, but I think Motorhead has been more important in terms of influence. Even some early "black metal" bands like Venom have some Motorhead worship going on.
However, I'll say Stained Class is a better album than any Motorhead album. And no, there are no suicide messages in there!