The sunglasses in my proflie pic are Morgenthal Frederics, a boutique brand out of NYC, that set me back about $500! Yes, I know that is an insane amount of money to pay for sunglasses. However, I had been looking long and hard for a pair of aviators that look good on me for quite a while, and these were the first pair that did, so I went for it. Plus the girl that I am dating absolutely loved them on me, and as we know, we do a lot of things to please the women in our lives.
I also have some Gucci sunglasses that I've had forever as well as some Persol frames (the ones Daniel Craig wore as James Bond in his first movie). For sport and casual, I tend to favor Spy Optic sunglasses and have my eye on their Cooper frames.
I'm a biker and I wear contacts so when I ride, I need good glasses with the rubber or foam around them to block out any wind so my eyes don't dry out. The Wiley X that a couple of people mentioned previously are great riding glasses and I've worn those. Currently I ride wearing a pair of Maxx riding glasses that are some pretty decent shades and only run about $20.00.
I don't want to sound like a label whore, but in this case, there is something to be said about spending a little bit on quality sunglasses. The clarity does make a difference and my eyes tend to be a little sensitive so it keeps me from getting headaches. But again for riding my $20.00 Maxx frames work well, they just don't look as good by themselves when I don't have my bandana or riding gear on. Go figure.