People play games for different reasons. Some people play to win, to fulfil their need to triumph through a show of skill, logic or chance. Others play for the simple joy, unphased by who wins, uninterested in the finer points of the rules. For many, games are simply something to do with friends enjoying the social side.
That last point was the basis for my second reason for why I think you should try out Dungeons & Dragons. It is one of the most sociable games out there. I also believe that the other factors above are especially true for D&D; it can be played competitively or for the simple fun of playing a game.
Which leads me to reason #3:
Reason #3 – It has Something for every kind of Gamer.
Even if you take away the social side of gaming and strip away the inevitable fun that comes with playing any good table-top game, D&D at its core is something that can appeal to all gamers. No matter how or why you play games, Dungeons & Dragons has qualities that will appeal to you.