I have Tifosi Forza sunglasses with fototec lenses, as well as the Tifosi Slip sunglasses with interchangeable lenses.

I actually like the Forzas quite a lot; the fototec lenses work over a very wide range of light conditions, they fit my face and provide good coverage. Very light and comfortable too. They look a little geeky on me though.

The Slips are a tad heavier and I notice this, but they are still comfortable, even for running. The thing that bugs me about them is that they have a substantial vent at the top of the lens, which does actually seem to help keep them from fogging, but in the summer on long rides I feel like all of that air rushing past my eyes makes them dry. On the other hand, it's nice to have at least one pair of interchangeable lens glasses for when you want to ride at night with clear or light yellow lenses. And the shape of these is very flattering on my face for some reason. Gives the illusion of great cheekbones.

I ended up with Tifosi's because they're so reasonably priced -- I think each pair was between $50 and $60. Someday I'll splurge on something schmancier, but for the time being these were a good value.