Here's a very obscure roots tune by a group called the Randells, 'Brimstone and Fire'. It's got a ruff bass and really nice plinky guitar. The singing's not the smoothest but that's OK, the lyrics are righteous and it's got a good vibe.
The real star on this record is the dub - play it loud on a system with plenty of bass - it sounds amazing.
Hope you enjoy.