We usually fly into Salt Lake for our yearly pillgrimage to the Wasatch early enough to take advantage of Park City's QuickStart...a program that lets you ski a half day for free at any of the Park City resorts (PC, The Canyons, or Deer Valley). This year, unfortunately, we couldn't get an early enough flight out, so we settled for Alta's ski-after-three program; where you can ride the Sunnyside lift without a ticket after 3pm.
The ski-after-three is a great alternative to the Park City QuickStart. While the QuickStart is a better deal--a half day at the Canyons (my personal favorite in PC) is greatly superior and more of a bang-for-your buck--spending an hour and half at Alta is truly bliss. Alta is my favorite ski area because of the terrain, snow, scenery, and the laid-back approach of the resort.
The snow at Alta is always amazing. It had been a week since the last dump, and there was plenty of shin-deep chopped powder in the trees and through the gates (yes, there's gates off of Sunnyside...you don't have to ski groomers the whole time). We made plenty of laps in a the 1.5 hours we were afforded, and found plenty of challenging terrain. The Vail Ridge is your best best if you want something non-groomer and a bit more off-piste. The chair passes right next to it on your right as you head up.
To take advantage of the ski-after-three is simple: just park at the Albion base parking lot, or the main lot by Collins chair and take the tow rope over. Then, just ski up to the Sunnyside chair. The lifties will take down the gate for badging your ticket through, so you can ski right up and get on a chair, no questions asked.
Sunnyside is only a fraction of the resort, but it's a damn good warm-up once you get into Salt Lake. If you can't take advantage of PC's QuickStart, or if you want that real, authentic ski-town vibe on the cheap (Free!), hit up Alta.