Tom Colicchio, Kate Walsh, Sam Waterson

The holidays are upon us, and that can mean only one thing (other than gorging on various seasonal treats) — marathon madness! Check out TVGuide.com's round-up featuring the must-see marathons of the season.

Bravo

Dec. 23
Flipping Out: 9 am — 5 pm/ET

Dec. 24
Top Chef: Chicago: 10 am — 4 pm

Dec. 25
Top Chef: New York: 9 am to 3 pm/ET
The Real Housewives of Orange County: 3 —11 pm/ET

Dec. 26
The Millionaire Matchmaker: 11 am — 3 pm/ET

Dec. 31
Project Runway: 10 am — 6 pm/ET

Showtime

Dec. 28
Original Series' Finales: 8 pm — 12 am/ET

Dec. 31
Comics Without Borders: 12 — 4:30 am/ET

VH1

Dec. 25
I Love Toys (Hours 1-5): 9 am — 2:30 pm/ET

Dec. 31
I Love the New Millennium: (Hours 1-8) 12 — 8 pm/ET

SoapNet

Dec. 25
General Hospital Best Holiday Episodes: 8 — 11 pm/ET

Jan. 1
Private Practice: 9 am — 7 pm/ET

SciFi

Dec. 30
SG-1: 8 am — 4 pm/ET

Dec 30 — Jan 2
Twilight Zone: 8am (12/31) — 6 am/ET (1/2)

TNT

Dec. 24 — 25
Law & Order: 2 am (12/24) — 8 pm/ET (12/25)

Jan. 1
Bones: 6 am — 12 am/ET (1/2)

TBS

Dec. 24 — 25
A Christmas Story: 8 (12/24) pm — 8 pm/ET (12/25)

Lifetime

Dec. 31
2008's Top Original Movies: 8 am — 12 am/ET (1/1)

Animal Planet

Dec. 25
Dogs 101: 7 — 11 pm/ET

Dec. 26
Whale Wars: 4 — 11 pm/ET

A&E

Dec. 24
Dog the Bounty Hunger: 8 am — 10 pm/ET

Dec. 25
Cold Case Files: 8 am — 8 pm/ET
First 48: 8 pm — 4 am/ET (12/26)

Bio

Dec. 24
Biography: 8 pm — 5 am/ET (12/25)

Oxygen

Dec. 24
Janice Dickenson Modeling Agency: 8 am — 4 pm/ET
Bad Girls Club: 4 — 7 pm/ET

Dec. 25 - 26
Snapped: 8 am — 3 am/ET (12/26)