Our first date was at Sapporo Revolving Sushi, so you know it's good. You can order a whole meal or purchase one small plate at a time to try them all. Even more fun: the sushi is delivered to your table by a robot or conveyor belt. Our favorite is the 'popcorn lobster'.
Container Park is walkable to the Grand Downtown Hotel. The shipping container complex has a mix of unique shops, restaurants, and bars: perfect outdoor setting for October weather. Oh, and the praying mantis sculpture shoots fireballs into the air.
Driving the loop at red rock is well worth the $15 per vehicle. We go rock climbing most Saturdays, usually hiking in from the second pullout. The third pullout, called Sandstone Quarry Overlook, has "Calico Tanks Trail", a beautiful 2.2 mile hike with a view of the city.
If you've got time and interest while you're in town: Willow Beach Marina is about an hour's drive from Las Vegas and a beautiful spot for kayaking (rentals available) or a beachside picnic. Emerald cave is about 2 miles up the river and accessible for beginner kayakers.
If you're up for a longer hike: Arizona Hot Springs Trail is 5.8 miles round trip and about a 45 minute drive from Vegas. The trail has natural hot springs at the end, closed up with sandbags forming natural jacuzzi tubs to soak in. Wear water shoes (or bring shoes to switch into like Chaco or Teva), swimsuits, and bring lots of drinking water.