The problem with romantic comedy in a TV series is the need for the romance to go somewhere - without going anywhere. Connect two characters who have chemistry, and viewers will clamor for them to get together. Let them hook up and pfft, the chemistry fizzles. (To television historians, this is known as the "Moonlighting" Principle.) Lifetime offers one possible solution: the romantic-comedy miniseries, less limiting than a movie but less pitfall-prone than a series. And the latest, "Marry Me," airing at 9 p.m. EST Sunday and Monday, turns out to be a charming option. Lucy Liu stars as Rae Carter, who wanted to be an artist but instead wound up in her fall-back job, social work. She's still hoping for a fairy-tale ending, though, if not in her job then in love with Adam, her boyfriend of two years. Rae thinks Adam (Bobby Cannavale of "Third Watch") is about to propose. He is - but not marriage. (Let's leave a few twists unshared, shall we?) The breakup aftermath finds Rae alone with her dog (a personality-plus pug) and eccentric family (Annie Potts plays her mother). Under pressure from her loved ones, Rae finally agrees to date and meets adorable Luke (Steven Pasquale, who played Sean Garrity on "Rescue Me"). Then she meets Harry (Enrique Murciano of "Third Watch"), Luke's super-wealthy friend. And just when you're wondering which is Mr. Right, Adam re-enters her life. Although the story eventually goes exactly where you think it will go, "Marry Me" is remarkably entertaining, and Liu (who co-starred on "Ally McBeal" and "Dirty Sexy Money") is as likable as she's ever been in what could have been a thankless role. Lifetime has already touched on every possible rom-com theme, and "Marry Me" revisits many favorites. But the luxury of time allows screenwriter Barbara Hall ("Joan of Arcadia," "Judging Amy"), who's also an executive producer, to tell the story at an enjoyably twisty pace, with a minimum of "oh, brother" moments. As a miniseries, "Marry Me" can come to its expected, satisfying conclusion with no concern for what happens next week. Ditto for movies, where romantic comedies have been a staple since before talkies. (See: Charlie Chaplin's "City Lights.") On television, though, where the hope is to continue a series as for multiple episodes and many seasons, family sitcoms and workplace ensemble comedies have been a safer bet for producers and networks in the post-"Coupling" era. This season, TV took a new shot at romantic comedy, with 50 -50 success. Fox couldn't score with eccentrically funny "Running Wilde," with Will Arnett and Keri Russell as a mismatched pair, but CBS found both humor and ratings in the romance of a plus-size pair (Melissa McCarthy and Billy Gardell) on "Mike & Molly." ABC has "Better With You," a hybrid family-romantic comedy starring Jennifer Finnigan and Joanna Garcia, which has been a middling success, with "Happy Endings" (with Elisha Cuthbert and Zachary Knighton as a couple whose split upsets their friends) due at midseason. Waiting in the wings at NBC is "Perfect Couples" (Jan. 20), about three couples trying to maintain ideal relationships, with the previously announced "Friends With Benefits" and "Love Bites" still in limbo. To a skeptic, all those premises suggest short lifespans. And even with a success like "Mike & Molly," you have to wonder where the story will wind up a season or five down the road. Will the writers feel forced to break up Mike and Molly (i.e., employ the Ross-and-Rachel Conundrum), or will they wind up married and settled, their only thrill sneaking brownies together?