iscrybe (http://www.techcrunch.com/2006/10/21/scrybe-could-set-a-new-standard-in-office-apps/)
I thought that was a great looking calendar app. I was digging it pretty well until I saw the paper option, which made it that much better. I like paper for most things since it means I don't have to mess around with having electronics everywhere I go.
I particularly like how they maintain context throughout all of the operations; I think this is really something that most applications are missing.