Looking for the perfect game ...

[Martino]

An adventure game ... third or first persson perspective ... free ranging ... open ended ... where you can be good, evil or neutral but where your actions have a butterfly effect on the world around you. And tonnes of NPCs. Does it exist yet?

[VV o n g B a]

i don't know any adventure games that allow this. only rpgs.

[TB4000]

Star Wars: Knights of the Old Republic. If you're not a fan of them, you may want to try something else, but it's basically got the requirements you were looking for.

[mr. x]

the Baldurs Gate series is great, II is even better and ToB is even betterer. a bit on the old side but great to have if your a mac user.

i hear Fallout series is pretty good too. its not a traditional sword and sworcery thing though, its a post-apocalyptic wasteland (think mad max) where u carry guns and stuff. but u have the choice to do a lot of things. iono about being evil but Deus Ex is a fps that gives u a lot of choice in terms of how to complete goals. u CAN shoot up civilians but that wont go down too well with the police cops though i spose its no different from Baldurs Gate. havent played it that much but Neverwinter Nights is sposed to be good too

[Chester]

i hear Fallout series is pretty good too.
Fallout was awesome in the scope of the world and the open-endedness of play. Really fun weapons and equipment too.

A caveat: anyone but the most die-hard of turn-based loyalists would get tired of the battle system and it had a ton of bugs that forced you to save constantly, due to the likelihood of progress-erasing crashes.