I love travelling to Vegas, but have never wanted to stay on The Strip, so this Holiday Inn Express is perfect, in more ways than one. It's close enough to see Mandalay Bay from the front of the hotel, and the shuttle will get you on the Strip in about 5 minutes, depending on traffic.
The staff are friendly, and professional, the lobby area is clean, and bright which seems to carry on throughout the hotel. The pool area is clean, which my kids always enjoy. The breakfast buffet in the mornings are great, some mornings the area is more crowded than others, but there's plenty of seats. I've used the exercise room once, and like that it's modern, and quiet, but located on the first floor across from the breakfast area, and front desk with constant traffic, so it's not isolated.
There's a gas station/convenience store across the road if you want to grab extra snacks, or drinks.
And the guest laundry room is a great convenience, I've never had a long wait to use the machines, which is a plus when you're living out a suitcase in Vegas with a family of 4.