11. Karmic Koala (9.10)
Flickr image credit: g_kat26
Everyone knows the adorable-looking koala, of course, native to coastal regions of eastern and southern Australia. Contrary to popular belief, koalas are not actually bears; they're also reportedly a lot more aggressive than they look.
Then there's Karmic Koala, the Ubuntu release from October 2009. Wouldn't you know, it focused on improvements in cloud computing using Eucalyptus. Pidgin was replaced by Empathy Instant Messenger, meanwhile, and the Ubuntu Software Center made its debut.