So as I bought Dark Souls and Batman:AA over amazon for cheap (cheaper than on steam), I followed the steam link on DS to a website about game mods and here are some links to the ones I liked the most.

SweetFX for Battlefield 3.
Sikkmod for Doom 3.
Wulfen texture pack for Doom 3.
ENB for Skyrim, but apparently for other games as well.
DSfix for Dark Souls (to fix the graphics port problem).

Enjoy! 

(if you have web links to other graphics mods that you think are exceptional, put 'em up. I think a repository of links here on FITES would be an excellent thing)