It's a balance. A game with a great story but terrible gameplay is as unplayable to me as a game with great gameplay and a terrible story. Both have to be at least good enough for me. It does depend on the type of game though. I don't expect an epic story out of say an action game, but I do expect it to be consistent and at least entertaining. I also rarely play a game for its multiplayer, so a good story adds replayability for me.