The nice thing is, you can pretty easily run both and switch around. Just get a distro with one, and then it's usually just 1 or 2 commands to get the other as a choice on the login screen. KDE and Gnome apps are also largely compatible, regardless of desktop environment.
I've been using KDE mostly, it's just nice being able to customize it so easily without too much technical knowledge of the environment or hoping someone already made an extension for it like on Gnome. Then again, some may like the simplicity of shopping around for extensions and calling it a day, or later even editing the extensions.
Recently, for my tiny laptop I switched to gnome, it's also just pretty :)