My favorite place to be in Las Vegas is at Cashman Field watching a Las Vegas 51s game.
This is high-level PROFESSIONAL baseball (Triple-A). It's a great opportunity to see future stars of MLB inexpensively and in a stadium that puts fans close to the action. In addition to the baseball action the 51s have great added activities and promotional giveaways. Thursday nights offer $1 beers and if you ask around you might find some additional "secret" specials as well. For those who don't want to be out in the heat they can go to the Club Level Restaurant (open to all ticket holders) until the sun goes down. Make sure you have cash on hand. Parking is $4 (cash only) and some of the concession/beer stands are cash only. There are ATMs on site if you forget.
Tourists or anyone who has had one too many $1 beers can easily get a taxi to their hotel/home as there is a dedicated taxi call box outside of the box office.