The year is 1995. You're an eleven year old Star Wars nerd and your dad just bought a sweet new DOS' with, like, a whole MEGABYTE of RAM! What do you do? You get Dark Forces.
In retrospect, you may think its just a DOOM-clone. But it isn't. And when it was first released, the Jedi engine was hardly thought of as anything but a massive leap gaming. With Dark Forces, you can look up and down, crouch, and even swim! There's multiple floor levels - and many of those levels feature atmospheric effects and all of them have animated textures!
We're spoiled in this day and age. I recommend Dark Forces because not only is it actually fun to play, and the storyline is pretty engrossing, but its a blast from the past from when games were actually more than layers upon layers of quicktime events.