Best open world game on Steam?

[LCBADs]

Yeah, finally got some money and time to spare so I ask you, Facepunch, what's the best open-world game to get off Steam? If you want to, you can qualify your pick in terms of story or gameplay or exploration or replayability or what-have-you.

[highlight](User was banned for this post ("Choose for me [Cosmic Duck]" - Orkel))[/highlight]

[Patcher]

GTA IV for action and GTA stuff
Fallout New Vegas for exploration and RPG

[Tacosheller]

I'm not sure of the best, but I loved and am still loving Fallout: New Vegas.

[gol4z03]

I like just cause 2, finished it this morning actually.

[Missing User]

Gta iv

[Pridit]

If you're looking for exploration..

Just Cause 2

[MadPro119]

Red Faction Guerrilla is actually a really cool game!

[Foxoxo]

[QUOTE=MadPro119;26758217]Red Faction Guerrilla is actually a really cool game![/QUOTE]

It sure is