For a mere $50, you'll be able to buy the GOTY Edition for PS3 and Xbox 360, which will nab you the original game plus a bevy of amazing extra content. Here's the full list, courtesy of Rockstar:
Undead Nightmare – The one-of-a-kind experience that pits John Marston against a sinister zombie outbreak, along with its Undead Overrun survival-based multiplayer mode
Legends and Killers Multiplayer Pack – Adds to the Red Dead multiplayer experience with nine additional active competitive mode map locations tailored for multiplayer action, eight playable characters from Red Dead Revolver, the devastating Tomahawk weapon and more
Liars and Cheats Multiplayer Pack – Massively expands Free Roam multiplayer with Multiplayer Poker, Liar's Dice, Horse Racing with Combat and a slew of additional Gang Hideouts and Hunting Grounds. Plus it adds the action-packed Stronghold mode to competitive multiplayer
Outlaws to the End Co-Op Mission Pack – Six explosive and epic cooperative multiplayer missions to play with 2-4 players
Myths and Mavericks Bonus Pack – Features new fan-favorite multiplayer characters and all-new multiplayer locations to battle in
You'll also get all of the original pre-order bonus content, including the Deadly Assassin outfit, Golden Guns weapon pack, and the Hunting and Trading Outfits pack, the Solomon's Folly single-player gang hideouts and challenges (available for the first time on 360).
Also, this reminds me, Myths and Mavericks is out today, and its' free.