“Modern Family” (9 p.m., ABC): We usually dread the first day of school. But on

“Modern Family” (9 p.m., ABC): We usually dread the first day of school. But on “Modern Family,” prime-time’s best new sitcom, it’s sure to be packed with laugh- inducing moments.

“Glee” (9 p.m., Fox): Why are we smiling? Because “Glee” is on tonight, and the “cool kids” at McKinley High School are about to get a taste of their own medicine.