It's a pretty simple explanation why I like Bang!(click the British flag in the corner for English!) It's because Bang! is a spaghetti western turned card game where draw can mean pulling a card or shooting someone from across the table. The game itself has a fairly easy learning curve, though it definitely helps to play with someone who has played before.
There are four roles to play in Bang!: the sheriff, the renegade, the deputy, and the outlaw. In a given game, there will be only one sheriff and one renegade (except in certain expansions), but the number of deputies and outlaws will increase with the number of players. Generally the outlaws will be the largest group, at least equaling the sheriff and deputies. The sheriff is the only player whose role is revealed openly (with a big shiny badge!), and that player's job is to shoot the outlaws and renegade. The deputies are meant to help in this job, but as they're not always known to the sheriff, a lot of bluffing and "false deputizing" can be involved here. The renegade wants everyone dead; they can only win if the sheriff dies and the outlaws are also dead. The outlaws simply want the sheriff dead and anyone else is just collateral. Players also get to choose from a random set of two options for their character, each of which has a special ability.
Players start with a set number of life points and those life points also determine their starting hand size. The sheriff starts play, drawing two cards and playing as many as they choose. They can only shoot people within the range of their gun (using a Bang! card, from which the game gets it's name), beer heals them, and other various objects and items can enhance the special skills of each character. The mystery and bluffing that goes on in Bang! is what really makes the game shine. Much bantering and yelling has ensued in every game I've played, with players actively commenting on the actions of one another and trying to convince the sheriff of their roles.
I've played Bang! with family members as young as 9 (she won her first game!) and it's an game we play now and again at my gaming group. Bang! is easy to transport, quick to set up, fairly simple to learn, and because you play against players who can bluff and because each character has special powers, it can be challenging and complex despite how simple it is. It's a great game that can be played over and over because each session can be completely different than the last.