Xfce is fantastic.

I made the switch when gnome 3 happened and have never looked back.

It’s themeable enough for me - xubuntu usually looks pretty good, you can get the themes on Debian easily enough.

It’s featureful enough, while still being relatively lightweight.

But the best thing about it? It’s not opinionated. You can decide what goes on your bars/panels, where they go at what size etc.

+1 Xfce is also very easy to customize out of the box. I customized my environment using the defaults that are preinstalled and I prefer it's looks to windows.

I personally really like Xfce, but my philosophy has always been function over form, meaning I don't mind if it looks like it's from the last millennium as long as it doesn't hinder the performance of my device (Acer Aspire one, running Intel Atom).

Interesting thing is that you can use the same philosophy in everyday life.