My favourites were the text adventures, the first one I really loved was Snowball by Level 9. I just found a review online
http://www.crashonline.org.uk/06/snowbal.htm
But I especially liked the Zork series from Infocom. They called their games 'interactive fiction' and they had a great parser that let you type proper sentences (or nearly anyway
). I bought a 5 1/4 inch floppy disk drive just to play them! You can still get them for PC (and for free too) on the web.
http://www.infocom-if.org/downloads/downloads.html