HAPPY HOUR.But once Ms. Houstoun hits her stride, ''Happy Hour'' glints with her brilliance as an actor, writer and slithery-bodied dancer. She almost painfully evokes a slow and occasionally giddy capitulation to drunken, helpless loneliness by a character who rouses herself enough, as her slide continues, tohurl venom at a dreadful litany of targets that range from theme parks and ''kids with their noses in paper bags'' to ''NewLabor's virtual reality.''Jennifer Dunning. The New York Times.