Vegas has a couple.. Well, one is a park, the other is a parking LOT.
KLAS has one parallel to the 25s, on Sunset Road. They feed ATC directly there and broadcast it over FM radio. Great place to observe and listen to ATC, both during the day and night. New year's eve and July 4th, that lot is PACKED, as it is also a great place to watch the fireworks shot off from the roofs of the casinos. So imagine seeing that, along with arrivals coming in, plus listening to ATC. Better yet, imagine being on that flight that shoots the visual approach to 19L or 19R, and are greeted with fireworks!
The other place is KVGT. They have a park tucked between the thresholds of 12R and 7, off the intersection of Decatur, Cheyenne, and Lake Mead Blvd. ATC is piped into there as well. Calm wind runways there are 12L, 12R, and 7, so you get really up close and personal with the arrivals.
I haven't found better spotting areas in the CONUS, especially with features like those.