I used to go after specific tires for their various purported benefits (durability, design, features, etc.), but that was a long time ago. I've had Avocets, Specialized, a fair number of Panaracers, Vittorias (when I rode tubulars), you name it. But for the last 30 years or so I've just gotten whatever's on sale at the size I want. I haven't had any problems with any of them. Right now I have some old Contis on the Trek, Bontragers on the Fisher, and my wife has Serfas on her Panasonic.