Mayweather vs. Alvarez. MGM Grand vs. Caesars. Those matchups pale in comparison to the fiercest Vegas rivalry of them all: Hershey’s vs. M&M’s. This winter, Hershey’s World opens at Monte Carlo—that’s practically right across the street from M&M’s World! The tale of the tape ...

Entrance:

M&M’s: Peanut M&M underpass

Hershey’s: Hershey’s Kiss-shaped doors

Customization:

M&M’s: Design your own M&Ms

Hershey’s: Design your own Hershey’s Kiss plumes

Spectacle:

M&M’s: 3D movie, I Left My M in Vegas

Hershey’s: 18-foot-tall Reese’s Peanut Butter Cup

Bottom line:

Who knows—maybe the rivalry will benefit both shops. In Chicago, Hershey’s is right across the street from Ghirardelli, and both spots have been jam-packed with tourists for years.