If nothing else, the stack-oriented workspace approach. I tend to use one workspace per active project, with anywhere from two to twenty windows on each workspace. As I type this, I have seven workspaces on this system.
And that's seven dual-1920x1200-monitor workspaces, mind you.
I love that I don't need to take my hands off the keyboard most of the time. I love that it's all dynamic. I love the simple, austere approach that stays out of my way. I love the lack of a "desktop".
I don't care about nautilus, or indeed most of the "gnome ecosystem" -- Just the gnome-shell, and the various applications/tools/whatever I use regularly. It Just Works.
Oh, as an anectdote, my linux-illiterate roommates figured out gnome3 all on their own (ie, how to launch a web browser, file manipulation, removable media) without so much as a single question. (Contrast that to them managing to get the old Win7 install rooted within two days...)