You should probably own Leonard Cohen's first three albums: Songs of Leonard Cohen, Songs from a Room and Songs of Love and Hate. If you can't pony up the cash for this unparalleled trio of testimonial folk, opt at least for the above compilation, which combines great tracks from each.
Few come close to Cohen's emotional depth and lyrical sophistication, and no one ever poured out more onto wax. Lines like "You held onto me like I was a crucifix" and "I'm cold as a new razor blade" are standard fare among this author's gems. "So Long, Marianne" showed that Cohen's sunnier side could be just as powerful as the bleak, brooding work he's remembered for today.