The best and easiest option when you are getting to the strip! You can get to the stop from either terminal 1 or 3. But terminal 1 is the easiest since it stops there anyway.
Wait till you get on the bus to pay and it'll be only $2/person. It came on time and it was a quick and easy ride. We took it to New York and it dropped us literally right in front of it. It was only the second stop, also. Easy peasy.
There's no other way to go except northbound, so that's the one you want to take to get to the strip. Northbound/Westbound will take you all the way to the end of the strip and I believe it even goes to downtown.
Take this bus instead of another shuttle or a taxi. It will save you a serious amount of time and money!