I discovered this while going through the blocks of Looney Tunes on Boomerang. (But they're only available until April 1st.) In the order they're listed:

"False Hare"
"The Abominable Snow Rabbit"
"What's Up Doc?" (incorrect release date of 6/17/60)
"Showbiz Bugs" (sic)
"Barbary Coast Bunny"
"Napoleon Bunny-Part"
"Bully For Bugs"
"Duck Amuck"
"Rabbit Seasoning"
"Big Top Bunny"
"French Rarebit"
"Rabbit of Seville"
"Rabbit Fire"
"Bunker Hill Bunny"
"The Windblown Hare"
"Rhapsody Rabbit"
"Fair and Wormer"
"Acrobatty Bunny"
"Buckaroo Bugs"
"Bugs Bunny Gets the Boid"
"Wabbit Twouble"
"Tortoise Beats Hare"
"Carrotblanca"
"Invasion of the Bunny Snatchers"
"Box Office Bunny"
"Portrait of the Artist as a Young Bunny"
"Spaced Out Bunny"

Doing a search for "Looney Tunes" on my cable TV's "on demand" channel also yielded 10 episodes of New Looney Tunes, 38 episodes of the infamous Baby Looney Tunes, and the recent direct-to-video movie Rabbits Run (which isn't free), all only available until April 1st as well.

In recent months a sampling of episodes of The Flintstones, The Jetsons and Top Cat have been available on the "on demand" channel, though only for a short time. And during "Scoobtober" in October, a lot of Scooby Doo TV series are available, plus some of the direct-to-video Scooby Doo movies that usually cost $3.99 for a 48-hour "rental" are free.

EDIT: It occurred to me that maybe the reason for all of this Bugs Bunny (classic and recent) on the "on demand" channel is because Easter is on March 31st. (But if it is, why didn't they include "Easter Yeggs"? There's also a Bugs Bunny Easter special from the 1970's, which ends with Bugs (and Granny) letting Daffy "win".)

I just noticed today that another batch of classic Looney Tunes (and Merrie Melodies) is on my cable TV's "on demand" channel. This time there's a little more variety, including a few B & W cartoons:

"Fish and Slips"
"Hyde and Go Tweet"
"Knighty Knight Bugs"
"Birds Anonymous"
"What's Opera, Doc?"
"Napoleon Bunny-Part"
"Rabbitson Crusoe"
"A Street Cat Named Sylvester"
"Duck Dodgers in the 24 1/2th Century"
'"Duck Amuck"
"Ballot Box Bunny"
"French Rarebit"
"Rabbit of Seville"
"Fast and Furry-ous"
"Baseball Bugs"
"The Film Fan"
"Porky's Duck Hunt"
"The Fire Aarm"
"Flowers For Madame"
"The Foghorn Leghorn"
"Carrotblanca"
"Chariots of Fur"
"Freeze Frame"

"Fish and Slips", "The Film Fan", "The Fire Alarm", "Flowers For Madame" and The Foghorn Leghorn" are available until May 1st. The rest are available until May 3rd.

Rabbits Run and episodes of Baby Looney Tunes are still available on my cable TV's "on demand" channel, but New Looney Tunes are gone.

Only a small batch of cartoons this time, but a couple of interesting choices. These are available until May 31st:

"Hairied and Hurried"
"Guided Muscle"
"Gorilla My Dreams"
"Greetings Bait"
"A Great Big Bunch of You"

Rabbits Run and Baby Looney Tunes are still on my cable TV's "on demand" channel. And ten episodes of Scooby Doo, Where Are You? (all from Season One), ten episodes of What's New Scooby Doo? (all from Season One) and ten episodes of Be Cool, Scooby Doo! (all from Season One) are available until June 3rd.

Another small batch of cartoons, mostly Bugs Bunny. These are available until June 15th:

"Half-Fare Hare"
"The Hasty Hare"
"Hare We Go"
"A Ham in a Role"
"Hare Force"

Rabbits Run and Baby Looney Tunes are still on my cable TV's "on demand" channel. And ten different episodes of Scooby Doo, Where Are You? (from Season One and Season Two), ten different episodes of What's New Scooby Doo? (from Season One and Season Two) and ten different episodes of Be Cool, Scooby Doo! (all from Season One) are available until July 1st.

Another small batch of cartoons, including one directed by Norm McCabe and the first color Looney Tune. These are available until June 30th:

"Hawaiian Aye Aye"
"Heir-Conditioned"
"The Hep Cat"
"Hobby Horse-Laffs"
"The Heckling Hare"

Only four cartoons this time, but some interesting choices. These are available until July 15th:

"Honey's Money"
"The Honeymousers"
"Hop, Look and Listen"
"Holiday For Shoestrings"

Only four cartoons again, but they include two B & W cartoons from the 1930's (one of them a Harman-Ising Merrie Melody) and one with Charlie Dog. These are available until July 30th:

"Hop, Skip and a Chump"
"It's An Ill Wind"
"I Wish I Had Wings"
"A Hound For Trouble"

Back to five cartoons. All of them except "Kiss Me Cat" are in rotation on Boomerang. These are available until August 14th:

"Just Plane Beep"
"The Jet Cage"
"Knighty Knight Bugs"
"A Kiddies Kitty"
"Kiss Me Cat"

Five more cartoons, most of them starring Foghorn Leghorn. These are available until August 29th:

"Lighter Than Hare"
"Little Boy Boo"
"Leghorn Swoggled"
"The Leghorn Blows at Midnight"
"The Lion's Busy"

Five more cartoons, though a couple of them will be gone after tomorrow:

"Lumber Jerks" (available until September 13th)
"Lovelorn Leghorn" (available until September 13th)
"Little Orphan Airedale" (available until September 13th)
"Little Red Riding Rabbit" (available until September 4th)
"The Lyin' Mouse" (available until September 4th)

EDIT: On September 11th, "Little Red Riding Rabbit" and "The Lyin' Mouse" are back. Both are available until September 13th.

Five more cartoons. Some interesting choices, including the only time that Daws Butler got screen credit in a WB cartoon. All of them are available until September 28th:

"Merlin the Magic Mouse"
"Million Hare" (sic)
"Mother Was A Rooster"
"Mice Follies"
"The Merry Old Soul" (incorrect release date of 11/27/33)

Five more cartoons, most of them directed by Chuck Jones. All of them are available until October 13th:

"Now Hear This"
"No Barking"
"Much Ado About Nutting"
"Muscle Tussle"
"The Night Watchman"

Five more cartoons, including three B & W ones, one of them a non-Harman-Ising B & W Merrie Melodie that probably hasn't aired on TV since it was on Nickelodeon. (And Mel Blanc got to use his "Rochester" voice in both of the other B & W cartoons.) All of them are available until October 28th:

"Out and Out Rout"
"Now Hare This"
"Patient Porky"
"Pied Piper Porky"
"Pettin' in the Park"

Five more cartoons, two of them B & W ones. All of them are available until November 11th:

"A Pizza Tweety Pie"
"Porky's Cafe"
"Porky's Bear Facts"
"Pigs Is Pigs"
"Plenty of Money and You"

EDIT: I watched "Porky's Cafe" last night. Incorrect (1936-1937) music played over the opening titles. One thing that I never noticed when "Porky's Cafe" was being overplayed on "Late Night Black & White" is that it doesn't have a story credit. Did Rich Hogan leave for MGM at the same time that Tex did?

Five more cartoons, all of them B & W ones. All of them are available until November 26th:

"Porky's Pastry Pirates"
"Porky's Poor Fish"
"Porky's Five & Ten"
"Porky's Poppa"
"Porky's Railroad"

Five more cartoons, three of them B & W ones. All of them are available until December 11th:

"Prince Varmint"
"Putty Tat Trouble"
"Puss n' Booty"
"Porky's Tire Trouble"
"Porky's Super Service"

Five more cartoons, including a Harman-Ising Merrie Melody with Goopy Geer. All of them are available until December 26th:

"Rabbitson Crusoe"
"Rabbit Rampage"
"Rabbit Hood"
"The Rattled Rooster"
"The Queen Was in the Parlor"

EDIT: Last night I watched "The Rattled Rooster". It had its original titles restored. When did that happen?

It has been over a month since the last batch of classic Looney Tunes (and Merrie Melodies) disappeared from my cable TV's "on demand" channel, and none have taken their place. So it looks like that has come to an end. (But Looney Tunes: Rabbits Run and Baby Looney Tunes are still there.)

I might as well also mention here that on December 1st, classic Looney Tunes (and Merrie Melodies) disappeared from the Discovery Family Channel, less than a week after they cut back from two half hour blocks a day to only one half hour block a day. (But Jabberjaw, The Smurfs and The Sylvester & Tweety Mysteries are still on the Discovery Family Channel. And at the beginning of January, Baby Looney Tunes returned to the Discovery Family Channel, though only on weekdays, not weekends. I'm not going to bother to post the schedule here.)

I didn't even get to find out (and post here) all of the shorts that aired on the Discovery Family Channel and my cable TV's "on demand" channel because I was forced to stay at my sister's house, with no cable TV, TWICE because of back-to-back hurricanes.

It was nice while it lasted...