Above is a link to an older post I made about this issue. It contains screens of the issue and specs and steps taken.
I really thought the problem was solved. I really wanted to believe that when I got a new card, the problem would just go away.
Problem is, I got a new card, and the problem remains.
I swapped the card for a GeForce GTX 550 TI, although it probably doesn't matter since the problem is clearly independent from the card.
I have also tried swapping around the monitor cable and monitor. It was a long shot, but it had no effect either.
Its gotta be software. I've run driver sweeper and used ccleaner to get the registry about a billion times now. They must have missed something. This thing is driving me crazy! Any help would make me so happy at this point.
The problem is either the monitor or how the game was designed. Of the games you listed I've only played Mass Effects 2 and Fallout: NV.
The simple issue is that the game may have been designed with those banding issues. I don't recall any banding issues with ME 2, but it has been a while since I played it. Fallout 3 and NV have banding issues with the sky from what I remember. It typically happens when at dusk and dawn when light conditions changes.
If you have an inexpensive LCD monitor, then chances are you have a TN panel monitor. These monitors sometimes have issues when displaying color gradients because they are known as 6-bit monitors. Newer TN panel monitors seems have less issues with color banding, but it is still there. More expensive monitors like PVA and IPS are 8-bit monitors and they do not have any issues with color banding. Unless of course the source material has these issues, these 8-bit bit panels cannot make a bad image look better.
e-IPS panel monitors are less expensive than S-IPS, H-IPS and P-IPS panel monitors, but e-IPS panels are 6-bit similar to TN panels. However, it seems they are less prone to display color banding issues than TN panel monitors. Again, if the source material has color banding issues then nothing can be done about it.
The sky images for Skyrim is similar to Oblivion, Fallout 3 & New Vegas. It is how the colors of the sky is rendered. There is nothing that can be done other than redesigning the Creation Engine used for Skyrim not to display (or to reduce the effects of) color banding issues.
The problems happen in all my games, bar none. There is always one problem or the other. I was not trying to indicate that they only happen in limited circumstances. In fact, the other thread lists several games that are affected. At this point, there isn't a game without an observable version of these problems.
Also, this is a problem that had a definite start. It wasn't that I suddenly noticed these problems, it was that they suddenly cropped up. I have observed several of my games working as intended with all the same hardware, back a year or so before the problem started. So, I don't think it is either my monitor or the games (plus as I said I've tried different monitors with no luck). This is part of what lead me to believe it may be failing hardware.
I will try reinstalling the OS and getting back to you. Until then other suggestions are also welcome.