Microsoft recently release OneNote for iPad and it looks pretty awesome. The theme and graphics are really clean and the everything just looks really well laid out. Orientation rotation works great.
After playing around with the app, I couldn't help but think, 'Why can't Google make something this clean?' Is it against their culture to make something which doesn't immediately scale to multiple screen sizes? Perhaps their designers are more accustomed to designing for the web. Thus far there have been no Google apps for iPad where I have thought "this looks quite nice"... Some are even "quite":http://itunes.apple.com/us/app/google-books/id400989007?mt=8 "amateurish":http://itunes.apple.com/us/app/gmail/id422689480?mt=8. (I couldn't help but notice the last screen shot for the Google Books app for iPad is for a book called "Learning Android").
There are a couple of other Microsoft apps for the iPad that are also very well done and highly rated.