I am a big fan of Moleskin journals for numerous reasons. One, they come in various sizes and formats (blank, ruled, grid). Second, that nifty little pocket in the back is perfect for keeping miscellaneous scraps of paper with jottings. And lastly, that elastic band keeps the larger scraps of place nicely tucked in the journal.
I enjoyed this little Moleskin display of journals of various artists and writers who use the journal: