King's Quest
King's Quest I and II can be downloaded here:
http://www.agdinteractive.com/
King's Quest III can be downloaded here:
http://www.infamous-adventures.com/
Those of you who have played these games will find yourselves right at home. The updated graphics are wonderful, the music is great, and the voice actors have done an excellent job. It is interesting to note that the man who did the voice of Graham in King's Quest V volunteered his time and voice to these games. Both King's Quest I and III are direct 1:1 remakes as far as the story and puzzles. King's Quest II was considered by many fans to be lacking in plot and illogical puzzles. This version of KQ II has an updated plot and the puzzles are better. So while the game will seem familiar, you will find that there is better character development, an expanded story and better puzzles.
If you find you enjoy these games, you can find more adventure games at http://www.bigbluecup.com/. This is the website that created the Adventure Game Studio which is the engine that was used to write these games. The engine is also freely available for download; so if you fancy yourself a programmer and have always wanted to make your own game, you can do that too.