I'm going to post links and general info about all of the Mass Effect Mods I know of.
Mass Effect 2 & 3 Textures- This is definitley the best place to go for info for all of the texture mods for 2 & 3. I had a torrent for all of the textures somewhere, if I find it again I'll make sure to link it here. Here's a link to the files
Mass Effect 1 Textures I don't have any experience with this one yet, so I can't comment on the quality. UPDATE- It should have an installer for the textures so you don't have to use TexMod.
If your system can handle it and you have more then 512mb of VRAM I would definitley reccomend using these mods along with the SweetFX mods. I was able to use ALL of them and it easily maxed out my VRAM(3-6gb) and actual RAM for the game(~2gb)