[gnusouth]

I really like XFCE's Thunar. In particular, the bulk rename feature is easier to use than any command-line tool and is really powerful. I use it for all my file renaming.

In the 10ish years that I've been using software I don't feel it has really improved much. I think my ideal UI is a traditional window with a few menu items and a really deep preferences window, like some of the software I used to use on OS X Leopard. Lots of recent software seems to sacrifice customisability in the name of simplicity (Windows 8+, GNOME 3, Ubuntu Unity). I don't think this needs to be the case, complexity tucked away inside menus won't ever bother users who want pure simplicity. I think lots of developers drawn to the "command-line-only" mindset would actually be happier with GUIs of this kind, but I'm speaking only from my experience (I use the command-line extensively, and Linux, not OS X).