Lots of choices, but don't rent in Denver - you're screwed if you have a problem
Rentals are all about the balance of convenience, quality, and willingness to schlep stuff around. Best rates will typically be in Frisco and Silverthorne (right of of Interestate 70, just before the Breck exists.
- No matter what, rent in advance online... save 30% and sometimes kids get their equip for free. Skirentals.com (Breezes) and rentskis.com (Breck Sports) are some good shops. I've heard Virgin Island Skis in Silverthorne is a nice outfitter too.
- If you rent on or near the mountain, it will be a premium, some of the Frisco/Silverthorne shops places have a Breck base location, so if you have a problem (boot size, etc), you can easily stop in.
- The higher end places have base camps - then you can change into your gear and store it each night.
- The highest-end places are like concierge services - they'll meet you at your place and set up you. They almost all have base camps on the mountains.
- Kids Skis: The younger kids may be able get skis as part of the ski school packages.
- Usually it's cheaper to rent for a week, than for 5 days. Look for online deals.