Maybe three's the charm for the Tribeca Film Festival, which just completed its third go-around (May 1-9) with...not a bang, exactly, but at least a promising pop. Sure, this year's fest featured the usual all-over-the-map lineup -- from Kate Hudson (''Raising Helen'') and the Olsen twins (''New York Minute'') to Jim Jarmusch (''Coffee and Cigarettes'') and the Van Peebleses (''Baadasssss!''). Not to mention a top prizewinner, China's ''The Green Hat,'' that may prove too artsy even for indie distribution. But for the first time since Robert De Niro and business partner Jane Rosenthal rolled out the fest in 2002, it seems ready to be about more than revitalizing lower Manhattan. Celeb turnout was high (Bill Murray, Claire Danes), attendance leaped 14 percent to 400,000, and entries improved (see sidebar). More importantly, Lions Gate bought first-time director David Duchovny's ''House of D'' (starring Robin Williams and Erykah Badu), which could become the festival's first crossover hit. At press time, three more deals were in the works, including one for the Anthony LaPaglia drama ''Winter Solstice.'' High-profile acquisitions are just what Tribeca needs to join Sundance, Toronto, and Cannes in the big leagues. ''There's no question we'll be a launching platform for studios,'' says Rosenthal. ''I don't have a crystal ball to say what's gonna break out, but it'll take that one picture.'' All eyes on you, Duchovny.