A gamemaster with a good story and the right players can make a horrible system worth playing. A friend of mine has run Bughunters (Amazing Engine) off and on for 10 years and we all love the story but none of us can stand the system, in fact we've gone diceless on several occasions. While I prefer a good set of mechanics they are only there to help the GM/DM and the players they don't make the story which is ultimately what it's all about. I will however concede that a horrible system or rules can ruin a good story.