The absolute best for all-purpose cooking is
enameled cast iron, specifically Le Creuset cookware. Easier to clean in most cases than Teflon. Lasts freaking forever. There's a reason that every high-class cooking show uses it.....and since they don't identify it or sell it, the reason isn't that they're getting paid to do it.
http://www.lecreuset.com/round-dutch-oven
Regular old-fashioned cast iron would be in second place. I think there's just one company in America that makes it now, but I could be wrong about that.