1. Zukitwo
currently, It’s my most favorite Gnome Shell theme on Ubuntu 11.10 (Oneiric Ocelot, I’m using beta version, stable will be out within few days). It looks great! The theme is available not only as Gnome Shell Theme but also as GTK 3 theme and GTK 2 theme, so even if you are not using Gnome shell or Ubuntu, you can try it in older version of Ubuntu. The theme has been updated frequently and the bugs has been fixed actively to work seamlessly.
