Michael Cera:
Comic Genius
America's Hugh Grant
FoolProof: Neither. He's an typically but not always funny kid. People seem to like him. Meh.  
Juno wasn't funny.
jhallway: definitely other. he was hilarious in Arrested Development, and he was only about 16. His internet shorts, Clark and Michael, are also extremely funny. His style was completely unique, but now it's starting to get old. He needs to come at comedy from a new angle.  
Hugh Grant was never funny.
Novelhead: In a few years, I could see him playing an "awkward boss" kind of character, like Michael Scott in The Office.