Knocked Up makes being hilarious look like a piece of cake.

Like Claire Danes, Katherine Heigl of “Grey’s Anatomy” fame makes the move from television to film with facility and grace. The conventional wisdom, that the audience either cannot switch off the TV character or that people will not pay to see an actor they can see for free every week, obviously does not ultimately hold true.

Heigl and our unlikely hero, Seth Rogen, play an accidental couple on the road to parenthood. They alternate, hilariously, between hope and horror at the prospect.

Leslie Mann (the director’s actual wife) and Paul Rudd provide excellent supporting work as a married couple who have been there, done that and come out of the process of matrimony and parenthood with quite a few dings and bruises.

Extras: 50 new minutes of material, video diaries with director Judd Apatow and Finding Ben Stone, the story of the “other” actors who were axed before Rogen.

Grade: A

Knocked Up is currently available.