There are a lot of choices. What I found interesting is that tires you would think should have low rolling resistance actually don't. Without comparative data I am now very skeptical of any claims. I spoke to my riding buddy today, he use to run the Vittoria open corsa and really liked them but went to the Michelin Pro 2 because they were easier to get. He had not seen this data but he had figured it out anyway - my respect for his bike judgement which was high just went up another notch.