Duke encounters a cola vending machine while blasting his way through a grocery store in Duke Nukem Advance for the GBA!
Here’s an earlier design for a Duke Cola machine that was cut from Duke Nukem Advance prior to the game’s release.
The 2001 E3 trailer for Duke Nukem Forever featured a quick glimpse of this cola machine!
Our hero takes a break to restore a few health points at this energy drink machine from Duke Nukem: Manhattan Project. Hail to the king, baby!
Duke stares down a Croak Cola machine in Duke Nukem: Zero Hour for the N64. Great find, Darren!
Duke Nukem invites you to suck down a Croke Cola in Time to Kill for the PS1! [Source]
I kept waiting and waiting on a screenshot from Duke Nukem Forever, and I finally found one! Thanks, @DemDarGrapes!
A generic cola machine in Duke Nukem 3D: Duke It Out in D.C.!
The same model reappears in Gearbox Software’s upcoming Duke Nukem 3D: 20th Anniversary Edition World Tour (in an image humorously titled red-ruckus-liter-of-cola.png on Gearbox’s website).