Acriz: Seems like most people here are just talking about preferences, but you can't base an argument on preferences. Hedwards statement was: A good game can stand on it's own, it can profit from a good story, but doesn't need to.
I didn't read all the messages, but I fully agree with that statement. So as I said, it is like the music in games. Not necessarily needed (depending quite much on the genre though), but when applied correctly, it can really add to the game.
Like Starcraft. A RTS game with a story? Yet, somehow it worked wonderfully, at least for me, even if most RTS games don't seem to care much for any story, and still they can be great RTS experiences. Starcraft's predecessor was Warcraft 2, and while their gameplay reminds each other quite a lot (even though the setting is different), I don't recall WC2 having any meaningful story either. It was mostly a string of unrelated missions getting progressively harder.
Ps. I sometimes see many suggesting that e.g. RPGs are heavy on the story and really need one to be RPGs. I guess this again how you define an RPG, or what do you think of as a story. I recall Darklands doesn't have much of a story, and I also consider e.g. ADOM as a RPG (of a rogue-like RPG type), and I don't recall it having any meaningful story either. If someone argues roguelikes are not RPGs, then I hit you in the head with Wikipedia:
https://en.wikipedia.org/wiki/Roguelike Nowadays though, it seems RPGs normally are quite heavy on the story. They wouldn't necessarily have to be, as examples above show, but they choose to be. In many cases it can make the RPG much more interesting if the story is good, true.
Adventure games... They also usually have detailed stories, but look where they started: ADVENT. What was the story? Find the pirate treasure from the caves, that's it. Is that a story, or merely an objective? Isn't ADVENT an adventure game, because it doesn't have a meaningful story?
It didn't have music either, for that matter. Pretty much all RPGs and adventure games have music nowadays, but that is not really what makes them RPG or adventure games.