Red Dead Redemption is THE Western-themed video game. While many Western-themed games have come before it, RDR offers the most complete and satisfying take on the theme, making you feel as if you're truly there, in the dying days of the Old West.
The gameplay is top-notch; it never grows old riding off in to the wild to find an animal of some sort to kill and skin, or to search for gang hide-outs and shoot up the bad guys who dwell within. Indeed, the game world is massive and is full of activity; the amount of side content and the rewarding nature of exploring the game's world will not leave you disappointed.
The game succeeds thematically, as well; each portion of the game's world is like a different Western genre, with New Austin representing the classic Old West, Nuevo Paraiso representing the darker spaghetti Western, and West Elizabeth representing a more modern take on the Western, symbolizing the death of the Old West and the birth of the modern age. And that's without mentioning the beautiful plot and excellent character development present throughout the game; John Marston isn't your typical "badass outlaw," but rather, a character that you will grow to empathize with and deeply admire throughout the course of the game.
Some would call Red Dead Redemption "GTA: Old West Edition." Well, I call it GTA perfected. Red Dead Redemption is one of those games that you have to play if you consider yourself even somewhat of a gamer.
Played it. Beat it. Loved it. One of the best games I've played in my life.