FOR TSE: I like the original photos better, too -- and since I was tagged in this post, I'll give an opinion.

I use flickr.com for my images -- and occasionally I'll come across photos that look like your filtered ones. The resolutions may be sharper but the colors are too intense. The sky can look positively frightening -- and I never use ones like that.

I had no idea how it was done. I assumed it was just a difference in camera equipment or processing. It's kind of sad to see it's deliberate. Often it just ruins the picture.