Tonight on TV: Letterman celebrates 20 years at CBS; Utah-USU kick off football season

David Letterman celebrates his 20th anniversary at CBS tonight on the Late Show (10:35 p.m., Ch. 2), and it's a bit of a blast from the past.Bill Murray, who was the guest on Dave's first show at CBS, is the guest tonight. And he arrives attired as Liberace because, well, because he's Bill Murray.As of tonight, the "Late Show with David Letterman" will air its 3,897th late-night episodes, in addition to four prime-time specials.Also tonight, the local college football season kicks off with an old rivalry on a new channel..Utah hosts Utah State in a series that dates back to 1892. The game will be televised at 6 p.m. on Fox Sports 1, a channel that dates back to Aug. 17.Other games tonight include North Carolina at South Carolina (4 p.m., ESPN); UNLV at Minnesota (5 p.m. Big Ten Network); Mississippi at Vanderbilt (7:15 p.m. ESPN); Rutgers at Fresno State (8:15 p.m., ESPNU); and USC at Hawaii (9 p.m., CBSSN)/Elsewhere on TV ...Motive (7 and 8 p.m., ABC/Ch. 4): A secret leads to murder; a teen is killed. These are the last two episodes of the season, and the ratings haven't been good so the prospects of a second season aren't good, either.High school football (7 p.m., Ch. 14): Logan at CottonwoodProject Runway (7 and 11:02 p.m., Lifetime): The contestants must choose a show and then design a look based on that shoe.Big Brother (8 p.m., CBS/Ch. 2): The head of household competition takes place.Rookie Blue (9 p.m., ABC/Ch. 4): Traci oversees a drug sweep.Hollywood Game Night (9 p.m., NBC/Ch. 5): Celebrities, including Tom Arnold, Terry Crews, Emilie de Ravin, Jerry Ferrara, David Giuntoli and Hoda Kotb, play parlor games. This is the last episode of the season, and the ratings haven't been good so the prospects of a second season aren't good, either.Wilfred (11 p.m., FX): Ryan is put in danger.