Flagstaff is a very hip and popular metropolis in northern Arizona. Home to Northern Arizona University, the Arizona Snowbowl, and Lowell Observatory, the city has numerous attractions and interesting things to see, and is surrounded by the lush Coconino National Forest. The nearby San Francisco Peaks are the highest mountains in Arizona as well.
The city has a wonderful historic downtown area. Check out the Weatherford Hotel, Babbitt's mercantile, and numerous other funky shops and storefronts in the area around the elegant train station. Plenty of great restaurants are also nearby; chow down at the Dara Thai, the Beaver Street Brewpub, or Charley's at the Weatherford.
The pleasant climate in the summer draws thousands up from Phoenix on the weekends, so be forewarned and get a reservation. Flagstaff has plenty of motels, with everything from old Route 66 classics to expensive four star resorts and bed and breakfast lodges.
Winter draws the ski crowd, although winter here is relative. The mountains don't always receive enough snow to open the resort, but it's the best skiing in Arizona.
Nearby attractions include the Grand Canyon, the Navajo Nation, the Hopi Mesas, Meteor Crater, Route 66, Oak Creek Canyon, and Sedona.