Killing Floor/Shout Out

• Lots of them to Harry Enfield's Loadsamoney sketch character.

LOADSAMONEY!
>Money, money, money
DOSH!

• "Who do you think you are, bleedin' Action Man?"
• "I know, you're only supposed to blow the bloody doors off!"
• "Smeghead!"
• The KF_Aperture map is an outright Crossover with Portal
• The trailer for the Summer Sideshow event has a clot saying "Knife goes in guts come out"
  • There's also references to IT. The Circus Husk also has some very GLaDOS-esque lines...
• Some of the Christmas Zed quote I Just Want My Hula Hoop and Grandma Got Run Over By A Reindeer.
  • The Gingerfast likes to quote the fairy tale of the Gingerbread Man, and the Snow Husk quotes Frosty the Snowman and The Christmas Song.
• The new .44 Magnum is the same model as Dirty Harry's Weapon of Choice. Killing six specimens with one shot each without reloading unlocks the achievement "Feeling Lucky?"
• Equipping the knife makes you run faster.