http://satya164.deviantart.com/art/Gnome-Shell-Elegance-Colors-305966388. This awesome new theme for Gnome Shell has the ability to change colors automatically depending upon the wallpaper the user has at the moment. This would be very good for a user that wants a dynamically changing desktop experience whenever they choose a new wallpaper. So, download this theme and give it a go if you want a dynamically changing desktop theme.
Nord: http://0rax0.deviantart.com/art/GNOME-Shell-Nord-214295138. This is another quality theme for Gnome Shell. This one has a blue ice color scheme and is very good for a first effort.
Away: http://worldofgnome.org/away-gnome-shell-theme/. This is a Gnome Shell theme that is rather like the default GS theme whilst making something new at the same time.
Minty Gnome Shell theme: http://satya164.deviantart.com/art/Gnome-Shell-Minty-268492415. This theme gives Linux Mint colors to Gnome Shell. Nice theme for any Linux Mint users.
Tyr GS theme: http://worldofgnome.org/tyr-gnomeshell-theme/. A high quality Gnome Shell theme. Well worth installing for any fan of high quality dark desktop themes.
Viva Gnome Shell theme: https://github.com/vivaeltopo/gnome-shell-theme-viva. Another high quality dark theme for Gnome Shell.