Warren Buffett, of course, is easily the best investor of our generation, if not all-time. This article - which appeared in the December 12, 2009, Wall Street Journal is a worthwhile read.
One key "takeaway" is that sometimes the best investments are the ones you don't make. Buffett avoided alot of potential disasters over the last year (e.g., Lehman Brothers) while picking up some terrific deals (e.g. Goldman Sachs) in the same industry.