Reference to Black Ops:
1. have a door in a building that has the name plate Mason
2. Have a music tape 115 By elena Siegman. (Song plays in Kino Der Toten on Zombies)
3. Have a case with a ray gun in it
4. Make the same building have a machine where you could upgrade the Ray gun for 5000 caps. (Pack a Punch, *hint hint*)
Pokemon Reference:
Some sort of mission where (maybe a simulation similar to Fallout 3's Operation Anchorage) you travel to japan and in a building you find a hate (Maybe wearable) that's Ash's original hat in the shows first season.
http://www.polyvore.com/pokemon_ash_hat-rare_rules_ebay/thing?id=1196912
Modern Warfare 2 Reference:
1. in Either a torn up battlefield or some US army base you find an item called "Ghost's Facepaint"
2. Have a room in the US army base that has 3 old paintings in a room commemorated to war heros, they say "James Ramirez, Gary Sanderson, and Soap McTavish(I forget McTavish's real first name lol)"
(This is my best Idea)>>>
Infamous Reference:
If you haven't played Infamous you wouldn't know, but in Infamous at some point in the story you meet a guy and he asks you about two posters he made and which one you want him to hang up all over town. One is to fear you and One is to respect you as a hero. In a building in the game you would see the poster, and it would change which one you see based on your karma of good or bad.(if there is a karma system in the game)
http://www.facepunch.com/threads/771297-inFAMOUS-Posters-Loved-and-Feared
And thus are my stupid ideas.