God I love when they get serious. The carefree bunch is the biggest impression everyone, including the reader, has of them. I love their goofy fun too, don't get me wrong. It just shows their growth, potential, and Iruma's influence when the carefree smile disappear. It also has the bonus effect of surprising everyone all the time!
Gah!! Their PRESENCE!!!!! I love love love! Even Clara was straight faced!