Honestly, Circus Circus doesn't get enough credit for their relatively cheap and fun carni games at Midway. While I wouldn't recommend the hotel to stay (though there are newer/remodeled non-smoking hotel rooms that are now available), you can't deny the children their fun and games while they're in Vegas.
Games cost from 25 cents to $3 (that's cheaper than our local OC Fair, folks, and available 365). As it goes, the higher the cost the larger the prize. Most of their prizes are current, including Hello Kitty and Minions from Despicable Me. Most booths allow you to trade in your smaller prizes for the larger ones, if won from the same booth. Midway also has a fun and FREE acrobatics show performed every couple hours. It seems always crowded, even later at night, but the energy is vibrant and the kids (and adults) always love it.
There's also a small carousel themed stand/booth that sells fairly priced snacks and drinks. The best part is that the entire thing slowly rotates and has ample seating so you can take a load off from all the games.