I'm a pretty big Lubuntu fan. If you haven't tried the newer versions, it has changed a bit. It now uses LXQt instead of LXDE.
If I had to switch, I'd probably also pick Cinnamon. Cinnamon is also an awesome DE. I stick with Lubuntu because it's still my favorite distro, even with the change to LXQt. It's still fairly lightweight, intuitive, easy, and good at getting out of my way so that I can get my 'work' done.
But, Cinnamon is also a pretty sweet desktop environment. I have an LMDE install on bare metal that I use with some regularity. If LXQt had things like the spices, it'd be even more awesome.