The season finales crop up with greater regularity as the May ratings period continues. What to expect this weekend:

"The Amazing Race" names another winner in a two-hour season finale that starts at 8 p.m. Sunday on CBS. The hockey brothers seem the most formidable team. The finale ranges from bog snorkeling in Northern Ireland to a finish line in Washington, D.C. Not to worry: "Race" will be back next season.

"The Mentalist" delivers another season finale built around the Red John serial killer at 10 p.m. Sunday on CBS. Red John strikes again in the fifth season cliffhanger, and Laura San Giacomo guest stars as a social worker. CBS says that Patrick Jane (Simon Baker) has narrowed the suspects to seven. But don't look for definitive answers. Series creator Bruno Heller has said they will be offered in the series finale, and "The Mentalist" will be back next season.

"Once Upon a Time" and "Revenge" don't deliver their season finales until May 12. But there will be new installments Sunday. "Once," at 8 p.m., takes a detour into the 19th century world of the Darling family and "Peter Pan." ABC says that Emily plots her next move as Daniel's fiancee on "Revenge" at 9. Then the network airs the probable series finale of the low-rated "Red Widow" at 10. Some fine actors were swept up in a preposterous premise on that one.

The dramatic alternatives in cable include "Game of Thrones" at 9 on HBO and "Mad Men" at 10 on AMC.

Fox's animated sitcoms bring on guest voices Sunday. Sonny Rollins lends his voice to "The Simpsons" at 8. Tim Gunn of "Project Runway" visits "Family Guy" at 9.

As for Friday ... ABC shipped "Happy Endings" off to the dead zone of 8 p.m. Fridays, a time slot certain to doom this young adult comedy. The network presents two new episodes at 8 and 8:30. The latter is the season finale, and low ratings means it's probably the end as well.

A "Blue Bloods" warning: The Reagans will suffer a loss in the episode at 10 Friday, CBS says. The drama offers its third-season season finale next week.

Saturday's best bets include "Saturday Night Live," which is hosted by Zach Galifianakis at 11:30 on NBC. Of Monsters and Men is the musical guest.

BBC America delivers a full slate of fresh programming. "Doctor Who" starts the evening at 8. "Orphan Black," which has been renewed for next season, follows at 9. And at 10, "The Nerdist" welcomes guests Jack McBrayer ("30 Rock") and Eliza Dushku.