Do you use fast travel?

I was looking at the actual game folder, not the zipped downloads. That's fully patched, totally unmodded and, at least in the case of ME2 (not sure about ME), I do not have all of the DLC.

But that's beside the point.

Like I keep saying, the actual game takes up very little storage space.

Look in your "Data" folder of your Skyrim directory. Look at what files are largest.

Skyrim - Meshes.bsm (That's 3d models of everything) = 1.4 gigs
Skyrim - Voices.bsm (The voice acting) = 1.4 gigs
Skyrim - Textures.bsm (That's the images that go on the 3d models) = 1.3 gigs
Skyrim - Sounds.bsm (Sound effects and music) = 950 megs
Skyrim.bsm (You know, THE ACTUAL GAME) = 300 megs

In other words, you could have doubled the content of the actual game - you could have made the world map twice as large and had twice as many dungeons and doubled the number of quests - and that still would have had a negligible impact on the overall size of the game's files. The simple graphical files for the game's random objects take up over half the size of the whole game. Actual game content takes up less than a tenth.

The total size of the game's files have absolutely nothing to do with the actual amount of content a game has.

Thinking that the small size was due to compression instead of low rez textures was cute pre-release, but now it's just pathetic.

It won't be long before my game + HD texture mods get to be 15 GB.

Yes you are right about that. I did not know that zip files sizes and actual files sizes are a different size. It is 10g Mass Effect with all the patches and DLC's.