This topic has probably been done do death already... but I'm curious, damn it.
Everyone plays League for a different reason. From the (sometimes) amazing community, to the diverse champion pool, the competitive aspect, the chance to show off your skills in front of friends and others, or even just to have fun, there are many different reasons and ways to play this game.
What's yours?
I play to hang out with my friends from back home!
I'm originally from Massachusetts, so I don't see my friends too often, aside from video Skype calls. For us, playing League together is a fun way to catch up/keep in touch with each other - more now than ever, since we keep branching away from what we all once considered 'home'. :]
Because my Lord and Master Teemo Commands it.
I really dont know anymore... I guess i'm too committed due to time and money investment. But all i really get out of it now are negative or neutral experiences.
League of Legends.
You become addicted to it, and feel compelled to play because you remember the fun you've had in some of your previous games.
You go through champion select and feel the joy of starting a new game, bright and optimistic towards the future. You have your favourite champion, the setup looks good, you are doing well. Then, the inevitable descent. You realise you're stuck in a game full of players trying to make you as miserable as possible; you own team abuse and harass each other, the enemy team is made up of all the champions you hate playing against. You struggle through it all, and maybe even win the game, but you realise that the flamers and the frustrating champions sapped all the fun and joy of your achievement before you even got there.
But then, a little time passes, and you think maybe the next game will be better. Maybe your team will stay friendly. Maybe the enemy team won't be filled with those champions you hate. Maybe it will be one of those rare games decided by skill and fair matchups in an atmosphere of sportsmanship, and you'll feel that magic you once felt when you were newer to the game.
And so, you press on, press the SoloQ button once again, and the cycle continues.
Fun!
And because I love the characters. The lore may lack at times, but I love the fantasy that playing as these characters gets across. What shall I be today? An unstoppable predator? 
? A juggernaut of massive proportions 
? Or a silent killer, waiting to strike 
? The game is so much fun, so that's why I play.
I play because of the piss poor community.... to one day have hope that we can all come together and create the great nation of RITO
I was enticed by league because of the amazingly diverse world and the original and creative stories that came with the characters. I mean, there isn't many worlds where a sentient armadillo in spiked armor can fight against a shadow ninja and a steampunk robot.
It most certainly isn't the community else I'd have hauled ass ages ago.
I used to play because of the whole thing being awesome.
With the current lore limbo, one of my favorite champions getting removed for no good reason and lack of faith in Riots narrative, I play mainly with friends. My personal playtime has dropped significantly, but when I do play it's because I think LoL is still the moba with the best game mechanics.
I miss Trundle though. I wonder who's next.
I play league because all my friends on Skype got me into it and it something we all enjoyed doing together. I have so many fond memory for learning how to play league some of them make me cringed :P
