In this age of online policies and DRM that seems to be more of a hindrance to players than convenience to developers, people seem to forget that there was a time when developers were not only thankful for players of their games, but they also had a more creative way of telling them "thanks." Below are some of the most well known, and perhaps best examples.
Nintendo: The Legend of Zelda: A Link to the Past - Chris Houlihan
With a full fledged sequel finally on the way this fall for the 3DS after 20 something years, this is a great one to start off the list.
Way, way back, a gamer named Chris Houlihan won a contest held by the now long gone mag, Nintendo Power. Evidently, Chris was able to snap a pic of the elusive Warmech boss from the first Final Fantasy on the NES (like I said, it way, way back) and sent in the picture to the mag as proof. His prize was a room all his own, that was more of a crash prevention method than an actual secret. Beyond the chance of randomly happening upon in, gamers found a total of five different ways to get into the room.
Those willing to dash all around Hyrule with the pegasus boots would gain entrance to the room, and were greeted from a message from Houlihan himself, as well as a congratulations in the form of a cash horde.
The room would stay put in the Game Boy Advance port of A Link to the Past, but all mentions of Houlihan were oddly wiped.
Sony: Long Live Play commercial - Gamers everywhere
There's a good chance you saw this commercial making the rounds on the boob tube and internet alike. A small collection of soldiers make their way to a small tavern, to discover its chock full of a wide variety of characters from dozens of different video games. Athena and Kratos from God of War, sackboy of LittleBigPlanet, Sweet Tooth from Twisted Metal, and countless others, all soaking in the suds.
It's a cool enough concept that not only do these guys all unwind and have a couple of brews together, but to who or what are they celebrating? At first, it's just to a random gamer named Michael, until the camera starts to pan out, and viewers can see they've cheered a great many times to more than just Michael. They've actually all been raising a glass to all of us. You can watch the whole thing below.
Gearbox - Borderlands 2 - Michael Mamaril
Walking through the Borderlands 2's sleepy town of Sanctuary, there's an excellent chance you came across an NPC by the name of Michael Mamaril, willing to dole out a few of the bazillions of the game's guns at no cost from any number of locations. If you found the sometimes elusive Mamaril and accepted from him his gift of gun, you'd also be awarded with a trophy / achievement on top of the firearm. He's one of the few NPC's to offer something without sending players on some sort of quest first, as well as being one of the few generous characters in the game.
Mamaril was actually based on a character of the same name, a gamer who loved the first Borderlands, played it almost every day, even after being diagnosed with a terminal illness. Mamaril passed away in 2011 at the age of 22. Shortly thereafter, his friend Carlos wrote to Gearbox, asking them to deliver a eulogy by Mamaril's favorite character, the wheeling A.I, Claptrap. Not only did Gearbox fill Carlos's request, but they did him one better, choosing to ensure that Mamaril will live on virtually in the Borderlands world of Pandora, to aid gamers in their conquest against Handsome Jack.
Honorable mention - Nintendo: Metroid - Justin Bailey
A bit of trickery abounds here, as there actually is no Justin Bailey. Going old school again, JUSTIN BAILEY was a password for the original Metroid on NES that would have Samus in her skivvies, as well as don her with all game's power ups, save for the ice beam. On the flip side, it also made things a bit more challenging, as it reduced her to a single energy tank.
Popular theories about the identity of Mr. Bailey involved everything from a hardcore Nintendo fan to a developer of the game itself, but the actual truth never came to light.