Immersion is what games really have going for them, personally, and it's why I couldn't get into FF13 or give a fuck what was happening. Towns and npc interaction help me give a fuck. I like getting lost in an imaginary world in games, however realistic or fantastical it may be. I'm not sure if that really can be attributed to being "story" proper, per se.
You say this, and that ME1 doesn't have a good story, and say that Portal has a good story? OK
I like the way Portal's story was told, not the story itself, per se. I thought the way it manipulated the player's emotions, or at least mine, was pretty good. It set itself up nicely. You start alone in an isolated facility, you have no clue what happened to the others but there are hints. You go through trials and level by level as GlaDOS guides you from stage to stage, and abruptly tries to kill you out of nowhere. You realize that you're not the first person she has done this too. I didn't really expect it, and going up until the final levels of the game, it's pretty fucking awesome with a great final confrontation as you finally leave the building.
In regards to stories, I prefer vagueness than hitting you over the head like with every other game. I like how Portal leaves a lot of the story up to the player and doesn't wrap itself up in melodrama or explaining shit. I prefer the thought of "show me/let me experience it" than "tell me", which a lot of you seem to prefer for some reason. In any case, I like how in Portal, information is not always handed out. A lot of the story is told through visuals and straight up audio or in game clues that the player finds out on their own. Like the gender of the main character, or the hidden rooms with writing scrawled on the wall.
ME1 have a good story? Its story is certainly serviceable and enjoyable. But because something is enjoyable doesn't make it necessarily good either. It's story is fine on many fronts: it has a wealth of culture, it has a interesting world view, really well written character, but it's pretty standard fantasy -- human masturbation, sacred and mysterious macguffins, stock sci-fi -- and for me, at most, Mass Effect is entertaining. I wouldn't classify it as "great" in any respect in this area because even the characters tend to be underdeveloped -- and this is an area where Mass Effect 2 trumps the original, in terms of storytelling.
And this is the problem with nerds. They have no capacity to distinguish "good/great/fantastic" from "enjoyable". Because Terminator 2 has an enjoyable story does not mean it has a GREAT story, either. But this is gamers we're talking about. Because a story is enjoyable, does not mean it's great. There are so many components to stories: characters, plot, narrative, pacing, that when one critiques a story does not mean they dislike every single element.
Also, the labeling of people who like something as such and such as opposed to listening to why they like it just makes you look like a tool, especially if we're the same people who hate on being "rebellious".