I like Gnome. I think it has a clean, efficient style especially when compared to KDE or Windows XP which can be colorful , rounded, and shiny to the point of distraction. But there are some things that I think are missing, and some things that I think were done without much thought or for wrong reasons that negatively impact ease and efficiency of use. KDE has a tendancy to try to match Windows features (it also does a few great original things), but there are a lot of Windows features that are bad. Unfortunately, Gnome often does the same. At least it only does it sometimes, and is just as likely to borrow ideas (good and bad) from the Macintosh, and I also see a lot of creativity in its designs (both visual and software designs) -- though I admit to paying more attention to Gnome development than KDE.
I am also a programmer, and have used GTK+ to build programs, so I have some ideas about new GTK+ widgets that applications could use to improve usability and usefulness.
On this page, I gripe about the problems and brainstorm new ideas. Some of them are very small and simple and could be implemented and tested in about 30 minutes. Others are features that have no obvious implementation method. Others require restructuring or rethinking bits of Gnome's current design plan.
I choose to worry about Gnome because it is intended to be simple, clear and easy to learn, so any defficiency in that department really begs to be resolved. Plus, as one of the two most popular UI systems, improvements to Gnome will affect many people as well as be more visible to interested non-Linux users.