KDE is still my DE of choice for Linux machines. They lost their way around the 4.0-4.6 release, but KDE 5 has been quite good for me.
Dolphin is much better than it used to be as well. When that came out I was in the Konqueror4Life group, but honestly, they've done a very good job with it. For instance, in Konq I would have to head up to the menus to load a profile to emulate midnight commander, but in Dolphin they've conveniently put a split button right on top. And you can still add extensions easily with the download new services menu. It's a simplified version of what I used from Konq, but there's still more to it than I ever use. Still don't like it as much as Konq? Well, you can still use Konq for file management, they didn't take that away.
Same with things like the K menu. They've spiffed it up, but I don't really like the fancy new sliding/scrolling thing. No problem, right click->alternatives->pick your behavior.
Or the Control panel. Don't like it icon based? Configure->tree view.
I like KDE mainly because I can set it up EXACTLY how I like it, not how someone else does. And they don't seem overeager to go for the lowest common denominator by throwing out things people like.