The new sitcom Undateable (8 and 8:30 p.m., NBC//Ch. 5) comes to us from some very funny writers (the folks behind "Scrubs"). Its stars are a bunch of funny standup comedians, including Chris D'Elia, Brent Morin, Ron Funches and Rick Glassman."And yet, somehow, it never comes together. This sitcom about guys who aren't good at relationships isn't really ... good.It's not awful. But it's sort of ... meh.Too bad.Elsewhere on TV ...Stanley Cup playoffs (6 p.m., NBCSN): Montreal Canadiens at New York RangersNational Spelling Bee (6 p.m., ESPN): The championship rounds of the 87th annual event.NBA playoffs (7 p.m., TNT): Oklahoma City Thunder at San Antonio SpursHollywood Game Night (7 p.m., NBC/Ch. 5): This week's celebrity guests are Nate Berkus, Adam DeVine, Tony Hale, Arsenio Hall, Malin Akerman and Bradley Whitford.Hell's Kitchen (7 p.m., Fox/Ch. 13): The teams are reorganized.Labyrinth (7 p.m., CW/Ch. 30): Part 1 of a two-part adaptation of Kate Mosse's novel about two French women who share a common destiny despite being separated by 800 years.Deadliest Catch (7 p.m., Discovery): An alleged felon is trapped at sea.Last Comic Standing (8 p.m., NBC/Ch. 5): Auditions continue.Gang Related (8 p.m., Fox/Ch. 13): Ryan tries to stop a gang war and cover up his own involvement in what's happened.The Black Box (9 p.m., ABC/Ch. 4): Catherine and Joshua's father returns.