Widely regarded as the first ever hardcore record I picked this up the other day. The Middle Class - Out Of Vogue.
The 'first' argument is an old one and something that can be argued for and against, either way I think this is an important piece from a historical stand point. I haven't heard this in years but it first came out in 1978 around 6 months before Black Flags Nervous Breakdown. If story's are to be believed The Middle Class actually influenced Black Flag around this time too although that of course could be nonsense. What is true is that this is certainly an early blueprint for the fast paced snotty music that would come to be called hardcore as the 80's rolled in. Musically it's fairly similar to Nervous Breakdown era Flag.
This is a 2008 repress on blue vinyl. Looks great actually.