"How I Met Your Mother" 8 p.m. CBS (ninth season debut) — It's Robin and Barney's wedding on Long Island.

"The Voice" 8 p.m. NBC (fifth season debut) — The original four judges are back.

"Dancing With the Stars" 8 p.m. ABC — Bill Nye the Science Guy could be the first to go.

"The Blacklist" 10:01 p.m. NBC (new series) — James Spader plays a fugitive who turns himself in to take down other bad guys.

"Castle" 10:01 p.m. NBC (sixth season debut) — Did Beckett say yes to Castle's proposal?

"Hostages" 10:01 p.m. CBS (new series) — Dr. Ellen Sanders is supposed to operate on the U.S. president but intruders take her family hostage.