Text adventures were massive in the '80s and Infocom provided some of the best examples of the genre. I have fond memories of playing these on BBC Model B's and on the first stuttering attempts at PCs. Here is a selection of a few of their undisputed classics.

WARNING!: Gamers under 30 should be aware that these games contain no graphics whatsoever and require you to read and think!

Hitchhikers Guide to the Galaxy
Spellbreaker
Zork