The Format were principally Nate Ruess and Sam Means. The released two albums in their time "Interventions & Lullabies" and "Dog Problems" before going their separate ways in 2008, Ruess has gone on to form a new band, fun. The three songs I've stuck in here are all from the second album "Dog Problems", and show a band who knew how to write a chorus.
"She Doesn't Get It" (catchy tune with a Duran Duran reference thrown into the mix)
"Time Bomb" (Amazing tune that has ELO quality harmonies on the studio version)
"Inches & Falling" (first song of theirs I heard, was featured on the closing credits of the film "Wedding Daze" with Jason Biggs and Isla Fisher and written and directed by Michael Ian Black)