GAMES

Mafia II - probably the best game I have ever played.I don't think it requires much :)

A very good pc means 4+ gb ram or even 1gb? As usual dumb question brought even dumber comments like either Skyrim or minesweeper...

Bad Rats: the Rats' Revenge

The Fall's story was pretty enjoyable, as for me. But keep in mind, that the current game is only the first part of trilogy, so it got kind of cliffhanger ending.

Loom

Shadowrun Dragonfall - Director's cut

Planescape Torment

Vampire the masquerade Bloodlines

The Detail Just started playing this myself, so far I like it.

Why don't you share with us your pc specs first ? Maybe you can play The Elder Scrolls V: Skyrim or just Gran Theft Auto 3.
Or you can try Can You RUN It

LIMBO, Lone Survivor, Silent Hill 2.

Syberia games, Half Life series, Warcraft 3 + Frozen throne addon, Mafia and Vietcong

Knights of the Old Republic I and most of Knights of the Old Republic II

Legacy of Kain series