Even before the nation’s economy went south, the prime-time sitcom was mired in its own miserable slump. Ratings plunged, critics groused, shows fizzled, and throughout Hollywood, pink slips piled up.

“For a while there, we were looking worse than the auto industry,” said Christopher Lloyd, co-executive producer of ABC’s freshman comedy “Modern Family.”

But now something funny is happening in prime time.TV comedy is finally showing signs of life, thanks largely to a crop of new shows brimming with artistic ambition, stellar casts and an ingredient that had become scarce in recent years: heart.

At the forefront of this recovery is “Modern Family,” a hilarious, feel-good series that offers a new take on the family sitcom with a “mockumentary” device and a three-tiered focus on an extended brood. And then there’s “Glee,” Fox’s hourlong musical comedy that dares to blend earnest dance numbers with satirical humor.

Other new shows feeling the love from critics and viewers include NBC’s “Community,” a twisted sitcom about junior-college misfits, and two more ABC comedies: “Cougar Town,” which has Courteney Cox playing a love-starved single mom, and “The Middle,” with Patricia Heaton as the frazzled matriarch of a kooky Indiana family.

Meanwhile, among established shows, “The Big Bang Theory” on CBS has seen its ratings soar since moving to a new time slot behind TV’s most popular comedy, “Two and a Half Men.”

It all adds up to a fresh surge of optimism for a genre that had been pushed to the brink of extinction by dramas and reality shows. Last season, NBC, which scheduled 18 comedies in 1998, was down to four, and ABC entered the fall with just one comedy on its entire schedule.

If there’s a unifying element to the new shows on ABC and elsewhere, it’s a willingness to wear their hearts on their sleeves. As USA Today critic Robert Bianco recently pointed out, they have restored warmth to a form that had become “almost fatally chilly.”

Indeed, the prevailing sitcom tone of the past few years has been one of ironic detachment, cynicism and even snideness. Leading practitioners of this style include “Arrested Development,” “30 Rock” and “The Office,” shows that generally attract critics and Emmy voters but also tend to alienate many viewers.

“I think snarky comedy is a little bit easier to do. Sweet and earnest is not what writers generally associate with sharp comedy,” said Falvey. “But television is a medium where you welcome these people into your home on a weekly basis. You want characters you care about. You want to feel some warmth, not despair.”

On the other hand, viewers didn’t want the same-old tired, predictable sitcom tropes. Collectively, the new shows appear to be succeeding because they maintain a creative edge while also offering relatable, sympathetic characters who resonate with the audience.

Perhaps no new show has struck the balance as well as “Modern Family.” Created by Lloyd and Steven Levitan (“Just Shoot Me”), it’s the saga of a sprawling, highly diverse collection of siblings, kids and in-laws. There’s the patriarch who is newly married to a young Colombian trophy wife; his daughter and her suburban family; and his son, part of a gay couple who have just adopted a Vietnamese baby.