Suggestions: which RPG should I play first?

[farlaff]

 

Man, Steam has sometimes prices so awesome that it is hard not to buy games, even if you got no time for them :( . Well, I'm about to start a new RPG from the ones I bought earlier this year, but don't which one to pick first.

Here is the list! In order of interest: 

 

Dark Souls 

The Witcher: Enhanced Edition & The Witcher 2 

Dragon Age: Origins 

Deus Ex: Human Revolution 

Mass Effect 1 & 2 

Star Wars: KOTOR 1 & 2 

 

Be very glad if you guys can help me decide.