Anyone who rides a motorcycle and is using cheap sunglasses should check out Wiley X.
I landed on these. Initially I grabbed the Airbornes but they blocked way too much peripheral vision. I wear a full face helmet which naturally limits peripheral so a wide lens is critical.
These were only $90 vs $140 and I can change out the lenses myself. The light-adjusting lenses are supposed to be pretty nice but I just use the sunglass lenses for now.
They're really comfortable and thanks to the foam that wraps around the frame where it meets your eyes wind, dust, bugs, etc. are prevented from entering your eyes. The wind doesn't become a problem until about 95mph(actual, which is about 110 indicated on most bikes) so they do their job pretty damn well.
http://www.wileyx.com/MOTORCYCLE/index.aspx
On a side note, does anyone else think that polarized lenses are incredibly overrated? I just don't see the big deal.