Tom Colicchio, Kate Walsh, Sam Waterson 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)