Faster than the bus and cheaper than a cab, shuttle buses are the best mode of transport if you are planning to travel to and from the airport with luggage. With Airline Shuttle Corp, it is easy to book online (discounted) or you can pay at their information desk by the airport (by baggage claim). I had the liberty of flying in during the night when the buses weren't frequent anymore, and I decided to take the shuttle instead. Most people on the shuttle are tourists and gets dropped off by the strip hotels, so it is less lugging around your luggage and speedier service than public transportation. I'm definitely doing shuttles again when I go back to Vegas.