LEGO Star Wars
Original Release: 2005, Platforms: Windows, PS2, Xbox, GameCube, GBA
Back in 2005, if you told me that LEGO video game adaptations would be so popular, I would've laughed. But then a friend and I sat down to play LEGO Star Wars for GameCube... and didn't stop until we'd finished the entire game.
LEGO Star Wars was a fantastic game that was family-friendly, established a tone for future installments, and was hilarious to boot. It's also incredibly accessible, making it easy for anyone to jump in (or start playing with a partner) without punishing them while they get the hang of things. In fact, trying to "break" the game is a huge part of the fun; rushing around each level smashing everything that isn't locked down, including your fellow players and NPCs.
But best of all, it managed to do this without sacrificing the epic Star Wars tone, keeping the appeal of alien worlds, space battles, and fighting robots with lightsabers. While it's a giant parody, it approaches its source material in a loving way. For me, that went a long way towards making the prequel trilogy more engaging. The game even managed to use some clever twists to turn the co-op mechanics on its head, including a level where Obi-Wan and Darth Vader have to work together to survive explosions on Mustafar before they can actually fight each other.
And while we're talking about it: LEGO Star Wars' Episode 3 ending beat the holy hell out of Darth Vader's "Nooooooooo" moment, hands down.