There are several ingredients to making a successful romantic comedy. You need a compelling storyline, a heartbreaking turn in the plot, and a moment where the two co-stars reconnect (preferably by running at each other in the rain in slow motion) and kiss. Then, as long as you have a charming male lead and a beautiful female co-star, you can sell it to the masses.
In honor of Valentine's Day, Moviefone decided to take a look at which young actresses are best when it comes to romances. Who wound up on top? Check out our 20 favorite leading ladies under the age of 40.