How about a fun South Beach/Miami theme with lots of Art Deco and bright, fun colors. And you could do that with Cuban food, like Cuban Coffee (which could easily be added to the existing drink machine - Yay!), ropa vieja, picadillo...so much great Cuban food!
I think it would be full of lots of fun colors and people could easily supplement the theme with things we already have.
Also, I love the RUSSIAN THEME suggestion.