I suggest a stop at the general store in Blue Diamond (near Red Rock Canyon) - there is a historical marker there for the Pony Express trail.
Bonnie Springs Ranch (also near RRC) is a cheezy old west theme town; last time I was there, bikes were waived in, no entrance fee. It's mostly kid attractions & shows, but a fun stop if you haven't BTDT before.
Sunset from the AZ side of the Hoover Dam is a treat.
Ride the Strip. Only need to do it once, & you're set for life.
I understand that most guys that go to Pahrump (or is it Par-hump?) don't go for the race track. So I'm told. That's Vag-ass though, & arguably bad form with the misses along.
And you know its Vegas, baby...
