Good game to get with Garry's Mod?

[NTUser]

I made the first thread! I feel so special.
The summer Steam sale is going on, and I think I'm going to take the plunge and pick up GMod. I'm not a gamer in the slightest, I'm godawful at anything that involves, well, gaming. I have no idea which game to get with GMod (since apparently you have to do that). I was thinking Portal, since I might actually play that, but I'm not sure.
Is Portal a good game to get with GMod? Or is there something better?

 

[Laura Knotek]

I have no clue, but I'd be interested in seeing suggestions.

 

[BIGPADDY]

Portal a good puzzle game, you might as well get portal 2 as well.

Gmod is awesome look on YouTube to get a better idea.

 

[BIGPADDY]

Batman Arkham Asylum and Batman Arkham City those two are my favorite games of all time!