You must be kidding!I love Ubuntu!
Too bad ATI graphics have poor support.
AMD/ATi have very good drivers. One proprietary, and another one, fully open-source (and directly supported by AMD). Even the latest cards are supported in both "versions".
They have also good opensource driver for openSolaris and Solaris based systems.
AMD/ATi had have very very bad Linux driver for graphic cards and no openSolaris driver, but it's not true now! Other AMD's driver for Linux have been always more than good.