I am a great fan of these old, atmospheric and intense text-only masterpieces - games from Infocom like Beaurocracy, Mind Forever Voyaging, Enchanter, or old hits from Level9 and Magnetic scrolls.
The tradition is alive till today, with modern entries aimed to be true interactive prose rather than simple collection of puzzles. More can be found out at http://ifarchive.org
I recommend titles from Andrew Plotkin (Zarf) - Tangle in the web, So far and Change in the weather. Just grab an appropriate version of a z-code interpreter and you are ready to play!
The old language called z-code used by Infocom has been further developed, with it's current incarnation called Inform 7. It's an interesting language that uses statements and commands in descriptive, language-like form rather than symbolic statements known from other languages.
Are you interested in this kind of games? Have you used Inform to write something you maybe want to share?