go carts! lol (there's the cheap but fun smelly place on Rainbow, then 2 kickazz places: fastlap and pole position), Mt Charleston, Redrock (which you already did), Wranglers hockey games, ? ?
I know you said off the strip, but a really good show is at the Mirage. Terry Fator. He's a very good ventriloquist. He's entertaining and pretty funny. You guys should like it. http://www.mirage.com/entertainment/terry-fator.aspx
If none of that sounds good, there's always the bar! Oh wait, you said no bar.