An ally of Duke named Jenkins is instructed by Dylan to escort Duke to the Duke Burger, foolishly Jenkins runs across a bridge, whilst running across the bridge Jenkins is killed by an explosion caused by an Alien aircraft, Duke says "Damn it Leroy!" after witnessing his death.
During the second episode of the fourth season, Dr. Lee makes another reference to World of Warcraft, this time comparing a planet in the Pegasus galaxy that he and :Samantha Carter had gated to before to Elwynn Forest.
In the 10th episode of the third season they discuss the "silent passion" WoW. (Video)