I grew up in Las Vegas so I've been here a zillion times. The security lines can be long during peak travel times (Fri and Sun afternoons), there's a nice variety of food chains and random and expensive stores. I always pray I get to fly out of the A and B gates since it is waaaay less crowded and there's never a line for security. Since it's a big airport, it can take a long time to get from your car to checking in your luggage to your gate, so allow for some extra hiking time.
Of course there's cheesy Las Vegas crap all over the place and slot machines, but that's what makes this place so... Vegas. The TSA clowns are usually pretty easy-going and apparently the taxi lines are realllly long. So save time ad hire a limo. It probably costs about the same. Also, free Wi-Fi!!