I was bored enough, and looking around Azeroth, you can find so many references... I decided to post a few that I found... Sorry if this has been posted before / if I posted this in the wrong section o.o
Half Life - (I've already posted it: http://www.mmowned.com/forums/wow-ex...half-life.html)
Star Trek: Lenny "Fingers" McCoy, a references to Star Trek's Leonard McCoy
The Beatles: There's the obvious one in Un'Goro Crater, Ringo the Goblin. Ringo is the Beatles' drummer, and is known for his big nose. Goblins have large noses. But there's also another reference in Goldshire, the Physician 'Michelle Belle', a reference to the Beatles's song "Michelle Belle".
Pink Floyd: Innkeeper Floyd Pinkus in Thrallmar. There is also a draenei on Azuremyst Isle that says "How can you eat your pudding if you don't eat yer fish?", a reference to the song "Another Brick In The Wall 2" Where you can hear somebody shouting "How can you eat your pudding if you don't any meat?!"
Weird Al: The quest 'Red Snapper - Very Tasty!' on Azuremyst Island is a reference to Weird Al's movie 'UHF'
Snakes on a Plane: The easily noticed crashed plane in Nagrand that is covered with snakes.
Tenacious D: There's a shield called the "Tenacious Defender" with the description "It has the power to... Move you."
Stars Wars: You can receive an item called a "Power Converter" with the description "Next best thing to going to the academy."
Monty Python: There's a quest called "Bring Me Shrubbery!" An abvious reference to the Monty Python and the Quest For The Holy Grail movie, with the Knights of Ni demanding to get a shrubbery. And in Eastvale Logging Camp called Terry Palin that says "I'm a lumberjack and I'm okay, I sleep all night and I work all day!", a reference to Monty Python's Flying Circus's 'Lumberjack' skit.
Terry Pratchet 'Discworld': In Theramore Isle is an NPC called 'Captain Garran Vimes', a reference to Terry Pratchet's Discworld series character 'Captain Samuel Vimes'. In Duskwood, there is Darkshire's 'Night Watch', refering to Terry Pratchet's book "The Night Watch" (Terry Pratchet FTW, BTW)
Lord of the Rings: There's an item in the game called 'The 1 Ring'. Think about it for a bit.
Flintlocke (World of Warcraft comic series): At the Zeppelin Crash Site in Hellfire Peninsula (A reference to the comic itself, Flintlocke and his friends crash a Dirigible into Stormwind) you can receive a quest with a reward 'Flintlocke's Piloting Pants'
Ophra Winfrey: In the Temple of Talhamat (I think that's how it's spelled) the Innkeeper is called 'Caregiver Ophera Windfury'
Bio Dome: In the Edo-Dome in Netherstorm is an NPC called Pauly Shore. (I caught this one while listening to Weird Al's 'Albuquerque' where he mentions having to watch Bio Dome with Pauly Shore)
South Park: An Ethreal in Netherstorm sometimes say, "How do you kill that which has no life?" which is said in South Park's "Make Love, Not Warcraft" episode, featuring World of Warcraft.
And that's all I could find and remember for now (I went around looking for all the references I had found that I could remember ingame.) Enjoy, and feel free to add you own.
Edit: I'm also glad to say that searching for a writing all of these references down was fun, and gave me something to do for a good while