This is great, there are some really good covers. I think the Doors is the one I usually hear on the radio, and it sounds so much like the Animals too. Walls of Jericho was really great, also Muse and Joan Baez.
This also made me wonder who wrote the original. So I found out it was a folk song of many different possible origins. Also, it is usually heard as "the ruin of many a man", but some people think it might have originally been "the ruin of many a woman".