I have spent the last 4 winter vacations at the Marriott Streamside Vail, and have loved each vacation more than the last! The Streamside is close to the lifts, has it's own transportation with indoor/outdoor pool and hot tub. The on-site equipment rental facility is a big time saver and the ski rental techs are great. I will book again.
I know exactly what you mean in finding alternatives to driving from Denver to Vail. Going uphill in anything less than an 8 cylinder SUV w/ cruise control is a nightmare.
United and USAirways have flights from Denver to Vail but be prepared for sticker shock as flights 1-way can be quite pricey. If time isn't an issue, a very affordable, convenient and comfortable alternative is the ECO shuttle. At $3 bucks you can't beat that! You can relax, read the paper, enjoy a snack or take a nap plus have a great time meeting new people! If you have a broadband card, you can hop online.