Above the ticketing level, cool little mall of shops and food places along with slot machines to waste time waiting for your flight. Free Wi-Fi throughout the airport.
Not enough outlets to charge phones, computers in the Southwest rotundas.
TOURIST BEWARE: 1) Taxis have signs saying it is unlawful for them to take longer routes, but many will go the long way. Friends paid $32 from airport to TI cuz taxi took freeway which is ~3 miles longer (@ $3/mi). Also, some will try to take you via Las Vegas Blvd and probably be happy the meter is running sitting in traffic. I usually request they take Paradise.
2) Most airlines require check-in 45 min prior to departure (regardless if you are checking bags).
HINT: Some people don't know but if you are willing to hike, there is a security checkpoint between B & C gates that is accessible past Southwest Airlines on the ticketing level. I have never seen lines here more than a few people. You can access A/B/C gates.