May sweeps shifts into high gear with overlapping season enders and series finales. “Dawson’s Creek” (7 p.m., WB) wraps up its last season with a two-hour episode set five years in the future.

Bad news emerges as the gang converges for a wedding in 2008. Look for hugs, tears and film-savvy dialogue.

“Creek’s” 1998 debut marked a major milestone in the evolution of The WB network from the home of comedies (“Sister, Sister,” “The Wayans Bros.”) with predominately black casts and urban audiences, to a showplace for hormonally charged teen dramas with nearly all-white characters from a decidedly preppy caste. The “Creek” sensation begat “Felicity,” which made way for “Young Americans” and other J.Crew fantasy-dramas. Could “Smallville” and “Everwood” be far behind? Of course, “Creek” was not the first such show on The WB. The cult success of “Buffy the Vampire Slayer” also made the network a teen destination. The history of that show, which has since moved to UPN and ends its run next Tuesday, unfolds on tonight’s “Biography” (7 p.m., A&E).

• “That ’70s Show” (7 p.m., Fox), a teen show of a very different ilk, concludes its fifth season with a glance at graduation day 1978. The gang also contends with Fez’s possible deportation and Eric and Donna’s imminent departure for Madison, marriage and matriculation. But all of these momentous changes are merely fodder for cheap one-liners. This show has devolved into a crude and predictable showcase for obvious sex and drug jokes.
• “The West Wing” (8 p.m., NBC) ends its fourth season with President Bartlet reeling from the kidnapping of his daughter Zoey from a Georgetown nightclub. Some worry that the crime is the work of terrorists and fear that the commander in chief may go ballistic. Gosh, sounds like this plot was cobbled together from “24” reruns. On a parallel plot track, Toby becomes a father to twins and sees the bundles of joy as yet another reason to whine.

Tonight’s other highlights

• The last two finalists are named after a one-hour installment of “American Idol” (7:30 p.m., Fox).
• Scheduled on “60 Minutes II” (8 p.m., CBS): Two U.S. POWs discuss their capture and captivity in Iraq.
• The women in Andrew’s reject pile share their opinions of “The Bachelor” (8 p.m., ABC).
• A sniper targets pedestrians on “Law & Order” (9 p.m., NBC).
• A bride sports a new face for her trip down the aisle on “Extreme Makeover” (9:05 p.m., ABC).

Late night

Sean Hayes and Avril Lavigne appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno hosts Jerry Seinfeld, dog diving and music by Third Eye Blind on “The Tonight Show” (10:35 p.m., NBC).