probably the best of what's still considered a netbook is the Asus Seashell line, like this one. 12" screen and dual-core Atom CPU.
*edit* Darn, Mark beat me to the punch on the Seashell
The ASUS Eee 1215N is more of a laptop than a netbook, and it has the dreaded "Optimus" video switching hardware -- which locks you into using MS-Windows, and locks out other operating systems.