Do you remember ZORK?

I just discovered that you can play ZORK online.

I remember playing ZORK and Hitchhiker's Guide to the Galaxy in high school, or maybe ZORK was only in college. I loved those text based games that involved thinking instead of eye-hand coordination. Also, no hints and no clue what you were actually supposed to do to win.

Did you ever play these games? What were your favorite, long gone games?