Old PC games you used to like.

[Opa-Opa]

Plenty of the old point-n-click adventure games (especially by Lucasarts):

Dig
Full Throtle
Monkey Island Trilogy
Grim Fandango
Leisure Suit Larry (1)

And those RTS games ...
AGE OF EMPIRES II, BIATCHES
Starcraft
Warcraft
WARCRAFT II (AWESOME)
CIV II
and one of my personal favorites, though hardly 'retro' I guess....
Age of MYTHOLOGY
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for shooters I played a lot of
Giants Citizens Kabuto [sic]
Jedi Knight Academy
Wolfenstein
Doom
Heretic and others......

ahhh... how I miss those LAN parties.....