There was is an older thread of this that was posted back in 2008: http://ubuntuforums.org/showthread.php?t=1006177
But since computer technology gets better even in the passing of one year I thought of making a re-post.
So here I ask the Ubuntu Community what have you found to work best for you? What I really look for is something with an Ubuntu friendly video card; namely because I really want the graphics to be sleek and smooth. Other things I find important are a small screen size and long battery life.