Personally I think Andy Samberg from Saturday Night Live is one of the the funniest guys on television right now. His digital shorts are often the best part of the show and his comedy troupe The Lonely Island (along with Jorma Taccone and Akiva Schaffer) is often brilliant. What I love about his musical stuff is that most of it is not only funny but usually really catchy. For instance, here's the skit with Rihanna where he plays the character "Shy Ronnie" that cracks me up everytime: