Where: Tucson, AZ
How far: 38, 57, 81, or 107 miles
Price: from $25, perimeterbicycling.com
Why it's a must: No one will judge you for going all-out this Thanksgiving if the Saturday before you finish this calorie-torching course. It covers the base of three of Arizona's most beautiful mountain ranges, rising more than 9,000 feet. You'll also rack up good karma for the holiday season: The 32-year-old event, which draws some 10,000 cyclists, helps raise millions for various charities, including a new primary beneficiary that hasn't been announced yet. One possible roadblock: "Watch out for the river wash crossings," warns premier CTS coach Nick White. "Cyclists typically have to dismount and look for high ground through a dry riverbed."