The Hobbit
You shall not parser!
Text adventures, despite their rich and significant role in the history of computer games, are rubbish. They're boring, and you know they are. Things improved a bit with graphics, but it was still tantamount to chatting with a calculator about life insurance policies.
Then The Hobbit changed matters with a new take on the noun/verb text parser. By implementing this new form of text input (rather deliciously entitled Inglish), Beam Software created a far more immersive form of user interaction. Instructions could be entered which resembled natural speech patterns far more closely, yet were still entirely fathomable by the game engine. Coupled with a host of computer controlled, independent game characters who went about their own business across Middle Earth, real time gameplay and an innovative physics system, The Hobbit became a largely un-vaultable benchmark for all adventure games that followed.
Gamers also received a copy of Tolkien's novel along with the cassette, although the plethora of potential outcomes in the game meant it really didn't provide much of a player's guide. Over the years, people have dedicated much of their uneventful lives to finding and exploiting logic holes in the massive Hobbit system, such as getting drunk so the clever engine begins slurring its words, locking Thorin in a box and throwing him into a river (only to reappear from his watery grave none the worse for wear - a bit like Gandalf did a few years later) and harassing the system into smashing unshamable objects.
That a game can be continually rejuvenated by years of pointless endeavour is testament to the ingenuity and brilliance of its creation, making The Hobbit a text adventure for everyone; not just boring, greasy haired nerds (although they'd enjoy it, I've no doubt).