When it comes to holiday weekends, the TV question is: Which channels aren't having massive marathons?

We can't include them all anymore -- there are just too many. At least we can tell you about the longest, the coolest, the most essential.

advertisement | advertise on newsday

And, of course, the ones that most aptly salute the meaning behind Memorial Day.

(Find complete weekend listings at newsday.com/tv.

Military salutes

Movie marathons (AMC, Friday 9 a.m.-Sunday 6 a.m., Sunday 10 a.m.-8 p.m., Monday 3 a.m.-6 a.m., 9 a.m.-10 p.m.) -- War-filled lineup includes "Patton" (Friday at 1 p.m. and Sunday 2 a.m.), John Wayne in his Vietnam saga "The Green Berets" (Friday at 5 p.m., Saturday at 11 a.m., Monday at 1 p.m.), Clint Eastwood's "Flags of Our Fathers" and "Letters From Iwo Jima" (Saturday at 8 and 11 p.m.), "Apocalypse Now Redux" (Sunday at 12:30 p.m., all on AMC).

advertisement | advertise on newsday

Movie marathon (Turner Classic Movies, Sunday 6 a.m.-Tuesday 6 a.m.) -- Samuel Fuller's Korean War classic "The Steel Helmet" (Sunday at 4:45 p.m.) is among the highlights, also including Gary Cooper as World War I's "Sergeant York" (Sunday at 8 p.m.), the John F. Kennedy docudrama "PT 109" (Monday at 4:30 a.m.), best-picture epic "The Bridge on the River Kwai" (Monday at 8 p.m., all on TCM).

The Longest Day (Fox Movie Channel, Sunday at 7:30 a.m.; Encore Drama, Monday at 10:10 a.m. and 8 p.m.) -- John Wayne epic of World War II's D-Day invasion.

The Unit (Cloo, Sunday 6 a.m.-6 p.m.; Universal HD, Monday 6 a.m.-Tuesday 6 a.m.) -- Contemporary Army special ops do their thing in Dennis Haysbert series.

World War I in Colour (Sunday 8-11 p.m., Military Channel) and "World War II in Color" (Monday noon-1 p.m., Military Channel); "WWII in HD" (H2, Monday 9 a.m.-6 p.m.) and "Vietnam in HD" (H2, Monday 6 p.m.-4 a.m.) -- Archival footage gains startling new clarity in immersive docuseries.

Hellcats of the Navy (Antenna TV/11.4, Monday at 5 a.m.) -- Ronald Reagan and wife Nancy Davis starred together only in this 1957 feature. Military marathon continues through 2 a.m., including Humphrey Bogart in "Sahara"

advertisement | advertise on newsday

(8 p.m.).

Band of Brothers (Spike, Monday 9 a.m.-9 p.m.) -- Acclaimed 2001 miniseries of World War II in Europe, with Ron Livingston, Damian Lewis, Donnie Wahlberg.

World War II programs

Series marathons

The Tudors (BBC America, Saturday 6 a.m.-Sunday 8 p.m.) -- Entire Showtime series, starring Jonathan Rhys Meyers as much-married King Henry VIII.

The Mary Tyler Moore Show (Hallmark, Saturday 10 a.m.-10 p.m.) and The Bob Newhart Show (Hallmark, Sunday 10 a.m.-10 p.m.) -- Together again: comedy hits from CBS' legendary '70s Saturday night lineup.

Necessary Roughness (Cloo, Sunday 6 p.m.-Monday 6 a.m.) and Royal Pains (Cloo, Monday 6 a.m.-Tuesday 6 a.m.) -- Refresher replays before USA series' new seasons premiere June 6.

Perry Mason (Hallmark Movie Channel, Monday 6 a.m.-Tuesday 6 a.m.) -- Raymond Burr wins 'em all in standard-setting courtroom drama from '50s-'60s.

True Blood (HBO Zone, Monday noon-midnight) -- All of Sookie's Season 4, before fifth season starts June 10. (Also: catch-up special "True Blood: Conjuring Up Season 4" debuts Sunday at 6:45 p.m.)

Unscripted marathons

Pawn Stars (History, Sunday 4 p.m.-4 a.m., Monday 8 a.m.-9 p.m.) -- Marathon concludes with two new episodes.

Face Off (Chiller, Monday 6 a.m.-Tuesday 6 a.m.) -- Syfy's prosthetic movie makeup competition.

Top Gear (BBC America, Monday 8 a.m.-10 p.m.) -- Hot/cool vehicles tested in Australia, South Africa, Italy and China.