Whoa! Your girlfriend picked the right guy! Here're our suggestions.
For local color, definitely stop off at the Gambler's Book Shop at 800 S. Main Street, just down the street from the Plaza. Here, you can shop for everything from slot machines to dice; how about a nice plexiglas toilet seat inlaid with $100 bills?
The biggest Las Vegas souvenir store is Bonanza, at the northwest corner of the Strip and Sahara. You might be able to interest her in a life-size Wayne Newton blow-up doll.
If she's at all superstitious (and even if she's not), you'll have fun at Bell, Book, and Candle (1725 E. Charleston). This store has been here for at least 20 years; it's a Las Vegas landmark, selling all manner of lucky charms and talismans, herbs and oils, implements of black magic, and other spooky stuff. A similar store is Psychic Eye at 2250 E. Tropicana.
If she likes antiques, a great place is the Antique Sampler Shoppes, a sprawling warehouse full of stalls rented out by more than 200 collectors and dealers. You could spend an entire afternoon nosing around this one place. At the southwest corner of W. Tropicana and Jones.
If she's into costumes or vintage clothes, try Halloween Experience at 5800 S. Valley View, and the Attic at 1018 S. Main St. (combine the Attic with Gambler's Book Shop nearby).
A fun store is Serge's Showgirl Wigs in the Commercial Center at 953 E. Sahara. Serge's Wig Outlet next door has cheaper and goofier hairpieces.
One of the largest international food markets you or she has ever seen is the International Marketplace at 5000 Decatur Blvd., just south of W. Tropicana.
By the time you're done with all that, she might be ready for you to take her to Paradise Electro Stimulations at 1509 W. Oakey Blvd., selling devices that can only be described as a cross between physical therapeutics and adult playthings. Fade to black...