If you want only non-stops, what about IND-DEN-LAS-LAX. If you don't mind one leg with a connection (-SAT), consider IND/CMH/SDF-SAT-LAS-LAX, and visit the Alamo and Riverwalk in San Antonio. Obviously, at LAS you may want to see both the Strip and Fremont Street Experience at LAS. If you only stay at McCarran airport, you can play the slots for as long as you want.

Recently I've seen Dings between DEN-LAS (~$58) and LAS-LAX (~$48), although I would not be surprised if those prices go up a bit over the next couple of months.

Hapy travels.