What are those games that are landmarks in gaming that one should play in order to appreciate the medium?
The question came to me when I saw my sister playing Half Life 2. I have never played Half Life 2 or finished Half Life 1. I know it's a game important not only as because it plays well but because it also revolutionized the industry in engine tech and lighting and such.
I'm asking cause I want to know and play about games that did the same.


Thanks
I didn't find the right solution from the Internet.


References
http://www.neogaf.com/forum/showthread.php?t=1449014

animation video