Ray Ban's for about $120. They look professional enough for the cockpit and you can still use 'em anywhere. Make sure you haggle a free hard case outta the deal (avoids the bending/breaking/losing part). The Sunglass Hut I went to tried to screw me out of it until I said "No Thanks."

Of course...I talked my captain into buying a pair today and 10 minutes later he sat on them in the cockpit.