First graders truly think that they are the BEST. (Well, if you ask most first grade teachers about it, they'd agree, in my opinion! Also, they're the CUTEST, with kindergarteners coming in as a very close second.) Of course, most of them also think that they are the fastest, the smartest, the bravest, the coolest... Hmmm, time for a book about superlatives!
Judi Barrett, the author of Cloudy With a Chance of Meatballs, has the BEST book about superlatives. Ha! Just foolin' around a bit with language there for a minute, but Things That are Most in the World actually is a good book, and a great way to introduce a writing activity with superlatives. Here's a sample, quite likely to be the favorite page for many of your little guys: "The smelliest thing in the world is a skunk convention." The accompanying illustrations by Jon Nickle are perfect, this one being political skunks cheering their candidate, all of them wearing clothespins on their noses. There are 13 equally imaginative superlatives here, all likely to bring giggles and "oh, yeahs!!!" from your students.
You'll love the last page, where there's a reproducible that would be a great beginning for a class book or writing display.
Here's a cover you might like to use for the class book.
The download also includes this chart, in case your writers need a bit of extra inspiration. You can click on the cover image to get them both.