As for the use of memes among other references, looks like I got a bit carried away on this comment, skip to the end for a summary if you're not enthusiastic about the topic:

What works in one medium is not guaranteed to work in others, but this doesn't mean it can't. It's a bit of nitpicking, yes, but couldn't resist making the correction since I'm a big fan of intertextuality in fiction (including games) as well as other cross-genre/multimodal works such as pervasive games (see for example Studio P and their fabulous Truth about Marika).

True enough, memes are a difficult material to work on because of their short lifespans and obscure (pragmatic) functions. An average meme becomes old and stale (for the original audience) in a couple of days because of rapid overuse. However, those memes that do break into general (Internet) public (especially many those that originated from popular culture references) do not stop spreading since although the original audience is already dead bored with them, there are always new people to rediscover and redistribute them. Some of these memes eventually get integrated in netspeak, some make it into Internet phenomena that "surely everyone has heard of". Since it's practically impossible to include a fresh meme in the game (publication and distribution stuff takes long enough that the), we may as well pick some of the really old stuff like "All Your Base" (which are almost old enough to be funny again).

Right audience certainly plays a crucial role in what works and for whom. I've always found memes based on actual prank calls and similar trolling very boring - there's very little wit involved in just repeatedly confusing or irritating someone. Games and Internet, however, are not that far from each other (certainly more similar communities than Internet boards and talkshow-audience) - it's a very fair shot that a fair percentage of the people who will end up playing our game will know some old memes. Some of those people will find the reference amusing, others will be less enthusiastic, but then again that's the case with all easter eggs. I still kind of hope none of them will stop in their tracks and outright hate the game for a small handful of overused memes in there. :)

(tl;dr) To sum it up, I agree about you in that we should keep memes to a minimum and keep them pretty subtle - and the same goes for any easter eggs we'll have. Still, I don't feel like it's in any way wrong to make some references as long as they:
1) Preserve inner logic of the gameworld
2) Are likely to be recognized by someone
3) Do not stand out too much and aren't too frequent
4) Do not hinder the progress for those players who don't know what the reference is about

Carl: :DDDDDDDDDDDD: That'd be some viral marketing if we could do that live.

Kris: That just means you probably have a healthier "freetime spent in/outside Internet"-ratio than some. :D

Carl: I don't doubt that. :P

Nonetheless, I'd rather keep any meme references we might include subtle enough that they do not break the in-game realism too much.

For example:
Rather subtle: An individual US propaganda poster saying "For Great Justice"
Not subtle: Nazi interrogator asking the character if it is true that he likes mudkipz.

Kris: I fully agree, I've never watched a full episode of it myself, but the quote has become a pretty overused Internet meme.

OVER 9000!!!?

I like this, I think you've succeeded rather well in camouflaging the reference so that it shouldn't stand out too much. :)