I went through the discussion thread from 2007 and this year (so far) and I have compiled a listing of everything that anyone mentioned in those threads.
I plan on keeping this list up-to-date, so I will continue to add/delete/fix titles as mentioned.
Thanksgiving
Movies:
A Day of Thanks on Walton’s Mountain (TV Movie)
A Thanksgiving Treasure (TV movie)
Alice's Restaurant
Avalon
By the Light of the Silvery Moon
Dutch
Hannah and her Sisters (??)
Holiday Inn
Home for the Holidays
MST3K Episode 6.22 "Teen-Age Crime Wave"
National Lampoons Family Reunion
One Special Night
Pieces of April
Planes, Trains & Automobiles
Scent of a Woman
Son-in-Law
Squanto: A Warrior's Tale
Tadpole
The Daytrippers
The House of Yes
The Ice Storm
The Myth of Fingerprints
The Thanksgiving Promise (TV movie)
The Thanksgiving That Almost Wasn't (TV Movie)
What's Cooking?
TV Shows:
3rd Rock from the Sun: Gobble, Gobble, Dick, Dick
7th Heaven- Thanksgiving
8 Simple Rules - Paul Meets His Match
8 Simple Rules - The First Thanksgiving
90210 Episode 3.15 "The Kindness of Strangers"
According to Jim- The Empty Gesture
Alice - Alice's Turkey of a Thanksgiving
Alice - Who Ordered the Hot Turkey?
All in the Family “A Little Atheist”
Amazing Stories, "Thanksgiving" (1986)
Aqua Teen Hunger Force: The Dressing
B.C. - The First Thanksgiving
Barefoot Contessa- Thanksgiving for Two
Becker - "Sister Spoils the Turkey"
Bewitched, "Samantha's Thanksgiving To Remember"
Boston Public Episode 1.5 "Chapter Five"
Buffy the Vampire Slayer Episode 4.8 "Pangs"
Bug's Bunny's Thanksgiving Diet
Channel Frederator - Episode 107: Fredsgiving
Cheers Episode 5.9 "Thanksgiving Orphans"
Chuck- Chuck versus the Nemesis
Coach- It came from New York
Cybill Episode 2.8 "They Shoot Turkeys, Don't They?"
Dawson's Creek 3.8 - "Guess Who's Coming To Dinner" (Thanksgiving)
Dharma & Greg Episode 1.10 "The First Thanksgiving"
Dharma & Greg- Thanksgiving until it hurts
Dharma & Greg-Midwife Crisis
Diff'rent Strokes 2.11, 2.12/Hello Larry, "Thanksgiving Crossover"
Doogie Howser, M.D. Episode 2.10 "Don't Let the Turkeys Get You Down"
Ellen Episode 4.10 "Kiss My Bum"
ER-Scoop and Run (S13)
Everybody Hates Chris - Everybody Hates Thanksgiving
Everybody Loves Raymond - No Thanks
Everybody Loves Raymond- Fighting In-Laws
Everybody Loves Raymond- Marie's Vision
Everybody loves Raymond-Fish or Turkey
Everyday Italian-Thanksgiving Leftovers
Family Ties Episode 1.8 "No Nukes is Good Nukes"
Felicity Episode 1.9 "Thanksgiving"
Felicity Episode 2.8 "Family Affairs"
Food Network Challenge-Ultimate Thanksgiving Feast
Frank TV - Franksgiving (Pilot)
Frasier Episode 4.7 "A Lilith Thanksgiving"
Frasier Episode 7.9 "The Apparent Trap"
Friends Episode 01.9 "The One Where Underdog Gets Away"
Friends Episode 02.8 "The One With the List"
Friends Episode 03.9 "The One With the Football"
Friends Episode 04.8 "The One With Chandler in a Box"
Friends Episode 05.8 "The One With the Thanksgiving Flashbacks"
Friends Episode 06.9 "The One Where Ross Got High"
Friends Episode 07.8 "The One Where Chandler Doesn't Like Dogs"
Friends Episode 08.9 "The One With the Rumor"
Friends Episode 09.8 "The One With Rachel's Other Sister"
Friends Episode 10.8 "The One With the Late Thanksgiving"
Full House: Episode 1.9 "The Miracle of Thanksgiving"
George Lopez-Guess who's coming to dinner, honey.
Gilmore Girls Season 3: A Deep-Fried Korean Thanksgiving
Gilmore Girls Season 6: He's Slippin’ ‘Em Bread... Dig
Gossip Girl- Blair Waldorf Must Pie!
Gossip Girl- The Magnificant Archibalds
Happy Days, "The First Thanksgiving"
Hazel: 'Everybody's Thankful But Us Turkeys'
Hello Larry - Thanksgiving Crossover
Home Improvement - My Dinner With Wilson
Home Improvement - The Wood, the Bad, and the Hungry
Home Improvement- Thanksgiving
Home Improvement-Thanks but no thanks
Hope & Faith- 9021-uh oh
How I met your Mother - Slapsgiving
How I Met Your Mother Episode 1.9 "Belly Full of Turkey"
Iron Chef, "Turkey Battle" (1994)
Jericho - "Red Flag"
Jerky Turkey
Joey - Joey and the Bachelor Thanksgiving
King of Queens "Supermarket Story"
King of Queens- Loaner Car
King of the Hill - "Happy Hank's Giving" (1999)
King of the Hill - "Nine Pretty Darn Angry Men" (1998)
King of the Hill - "Spin the Choice"
King of the Hill - Bobby protests Thanksgiving
King of the Hill - Goodbye Normal Jeans
Linus the Lion Hearted - Thanksgiving
Little People, big world-A Roloff Thanksgiving
Living Single Episode 1.13 "Love Takes a Holiday"
Mad About You 7.7 - "The Thanksgiving Show" *
Mad About You Episode 1.9 "Riding Backwards"
Mad About You Episode 3.8 "Giblets for Murray"
Malcolm in the Middle -Thanksgiving
Mama's Family - An Ill Wind
Married with Children- A Bundy Thanksgiving
Martin - Feast or Famine
Martin - Thanks for Nothing
Miss Match - "Jive Turkey" (Thanksgiving)*
Moesha - "Thanksgiving" (1999)
Moesha - All This, and Turkey Too
MST3K Webisode - Thanksgiving Clown
MST3K Webisode - Turkey Bits
My Friends Tigger and Pooh - Many Thanks for Christopher Robin
Ned and Stacey Episode 1.10 "Thanksgiving Day Massacre"
Northern Exposure (S4) - "Thanksgiving"
Once & Again (S1) - "Thanksgiving"
Once & Again (S2) - "Feast or Famine"
Once & Again (S3) - "Chaos Theory"
Partners - "How Long Does It Take to Cook a 22-Pound Turkey?" (Thanksgiving)*
Paula's Southern Thanksgiving [Food Network]
Picket Fences Episode 1.9 "Thanksgiving"
Reba - "Invasion" (2005)
Reba - "Thanksgiving" (2004)
Roseanne - "We Gather Together" (1989)
Roseanne Episode 6.10 "Thanksgiving 1993"
Roseanne Episode 7.10 "Thanksgiving 1994"
Roseanne Episode 8.8 "The Last Thursday in November"
Roseanne- Thanksgiving 1991
Roseanne-Home is where the Afghan is!
Saved by the Bell: The College Years Episode 1.10 "A Thanksgiving Story"
Scrubs-My day off
Sealab 2021 - Feast of Alvis
Seinfeld “The Mom & Pop Store”
Sister, Sister - Thanksgiving in Hawaii
South Park Episode 1.8 "Starvin Marvin"
South Park Episode 4.14 "Helen Keller! The Musical"
Spin City-The Competition
Spin City-The Thanksgiving show
Sports Night Episode 1.8 "Thespis"
Sports Night: The Quality of Mercy at 29K (??)
Still Standing - "Still Thankful" (2002)
Tales Of The Wizard Of Oz - Gabe The Gobbler
That '70's Show - "Thanksgiving" (1998)
That '70's Show - "You Can't Always Get What You Want" (2004)
That '70s Show - Thank You
The Bernie Mac Show - Thanksgiving
The Bernie Mac Show - Tryptophan-tasy
The Beverly Hillbillies Turkey Day
The Beverly Hillbillies-The Thanksgiving Sprit
The Bob Newhart Show (S3) - "An American Family"
The Bob Newhart Show, "Over The River And Through The Woods" (1975)
The Brady Bunch "The Un-Underground Movie"
The Class: "The Class Gives Thanks"
The Cosby Show - "Cliff's Wet Adventure" (1989)
The Fresh Prince of Bel-Air - Talking Turkey
The Gumby Show - Pilgrims on the Rocks
The King of Queens - Loaner Car
The King of Queens - Thanks Man
The Parent 'Hood- The Parade-y Bunch
The Simpsons Episode 2.7 "Bart vs. Thanksgiving"
The State - Tape People
The Waltons: A Thanksgiving Story
The West Wing: Shibboleth
Titus: The Perfect Thanksgiving
Two and a half men-Merry Thanksgiving
Two-A-Days: Hoover High - Thanksgiving Tradition
Ugly Betty: "Four Thanksgivings and a Funeral"
Underdog - Simon Says ... No Thanksgiving
What I Like About You- The Wedding
What's Happening: "Mama, the School Girl"
Will & Grace- Queen's for a Day part 1 and 2
Will & Grace: "Homo for the Holidays"
Will & Grace: "Lows in the Mid-Eighties"
Will & Grace: "Moveable Feast"
WKRP (S1) - "Turkeys Away"
Yes, Dear-Guess who's not coming to dinner
Shorts:
Casper the Friendly Ghost - Do or Diet
Service For Four
Stella Shorts 1998-2002 - "Thanksgiving 1621"
Stella Shorts 1998-2002 - "Turkey Hunting"
Thanksgiving (2004)
Tom and Jerry - The Little Orphan
Other Links:
Inventory: 17 Memorable Thanksgiving Television Moments
Top Ten Best Thanksgiving TV Moments Ever