Little known fact about vegas cabs. If you tell the cab driver to take you the cheapest way they HAVE to go the cheapest way, you can report a cab that doesn't and they can be ticketed.
You may notice they always ask if you want the freeway (thinking it will be faster therefore cheaper) but it isn't.
When we had our wedding down there we used
http://bell-trans.com/las-vegas-limo...-of-las-vegas/ for shuttles and general transportation. Cheapest rates we could find and they were awesome to deal with