We gamers do love our nods to other media. From the earliest days of gaming and software, the easter egg has been a staple, something hidden without mention in the recesses of code. These days, we're as likely as not to have entire areas devoted to a drawn-out reference, or in some cases an entire element of gameplay added mostly as a long-standing joke. Some games have elevated the art of reference almost to an art form, with major storyline characters introduced as a sort of extended cameo from their original media.
Of course, that's also the problem with references: it can sort of cheapen the game you're playing if it's subtle, and it destroys immersion if it's mind-shatteringly overt. So what do you think? Do you like little snuck-in references to books and movies, or do you like your world to be totally consistent? Do you prefer it when the inspiration is kept under the radar, or would you rather just have the whole thing out in the open? What's your favorite instance of a game calling back to something else?