Ron Griess of The Chart Store looks to history for some analogies to the current market. He looked at 1938, 1942, 1974, 1982 and 2003. He rebalanced them to the same starting point, and noted highs and lows.
Here are 3 leading candidates — as I have said previously, my money is on 1974:
1938-45 vs 2008-10 Comparison
1973-78 vs 2008-10 Comparison