Good God, Guys! While Brighton is a good spot and the locals have their sure love for it, we're talking about a kid from Flat-a$$ Ohio who is looking to blow his mind on a trip. C'mon, man! Brighton isn't going to do it! Brighton is all well and good, but for 4 days of riding?!?
If you're taking mom on a vacation (or she's taking you, whatever) you'll need to consider her in the mix. You'll need a place where she can enjoy her time while you enjoy yours. Unfortunately, you're going at a rough time as New Years is still pretty early in the Season and the bases can, sometimes, be limited.
If you want walk-out to the lifts, then you may want to look at Vail, Breckenridge, Big Sky. All are going to be very very pricey because you're looking at a Peak time, for sure! If you go to vail, you can catch a shuttle to Beaver Creek for a day or two, thus giving you a little variety in your experience. You could probably spend all 4 days at Vail and have a blast, but the variety is nice. Actually, you may want to try the flip....stay at Beaver Creek and Shuttle to Vail for a day or two. If you went to Breck, you could shuttle to A-Basin...a Colorado equivalent to Brighton.
If you go to Utah, then you'll have to consider what you want. Park City will be good for mom and would provide your walk-out options, but I wouldn't suggest you spend 4 days riding PC. I Guess you could ride the Canyons which is a short shuttle/cab from PC, but the snowfall PC and Canyons get is significantly less than Snowbird/Brighton/Solitude. If you stayed in SLC and rented a car, you could hit Snowbird (no doubt, a North American Must-see!)and Brighton with a 30 minute drive to each resort. When I go to Utah, that's usually how I hit it. 2-3 Days at Bird, and a day at Brighton. Find the Cotton Bottom bar and grab a Garlic Burger.....sooo good! You could also take the scenic drive to Snowbasin (Corporate place, so many don't like the place) or Powder Mountain (Big Local Spot)
Another thing that is nice about Utah is that the SLC airport is 40 mins (MAX) from Bird to the Airport. I've been able to ride Snowbird till 2:30, catch my 5:00 Flight and be back to Philadelphia and in my bed by midnight. If you go to CO, the drive from the Airport to Summit Co is about 2 hours (give or take/depending on traffic)
I really can't speak about Big Sky.
Traveling the States and Taking Pictures